Common use of Duration and Exercise of Warrant Clause in Contracts

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 20% of the underlying shares from and after 9:00 A.M. New York City time on October 27, 1999 (the "Initial Exercise Date"); (ii) 20% of the underlying shares on October 27, 2000 (the "Second Exercise Date"); (iii) 20% of the underlying shares on October 27, 2001 (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27, 2008 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by the

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 20% of the underlying shares from and after 9:00 A.M. New York City time on October 27, 1999 (the "Initial Exercise Date"); (ii) 20% of the underlying shares on October 27, 2000 (the "Second Exercise Date"); (iii) 20% of the underlying shares on October 27, 2001 (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27, 2008 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by: (i) surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 3232 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M. on the Expiration Date (or 5:00 P.M. on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (ii) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company, subject to Section 1.5 herein) and (iii) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or, if permitted by subsection 1.5 and in accordance with the provisions thereof, such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares.

Duration and Exercise of Warrant. (a) This Warrant may be exercised as to purchase (i) 2025% of the underlying shares from and after 9:00 A.M. New York City time on October 27May 19, 1999 2001 (the "Initial Exercise Date"); (ii) 20and the remaining 75% of the underlying shares on October 27May 19, 2000 2002 (the "Second Exercise Date"); (iii) 20% of . The Initial Exercise Date or the underlying shares on October 27Second Exercise Date, 2001 (as applicable, is hereinafter referred to as the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27. This Warrant expires at 5:00 P.M., 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27May 19, 2008 2009 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of the outstanding voting securitiessecurities of the Company, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of the outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by (a) surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 0000 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M., New York City time, on the Expiration Date (or 5:00 P.M., New York City time, on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (b) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company) and (c) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares. (c) With the consent of the Compensation Committee, and subject at all times to, and only to the extent, if any, permitted under and in accordance with, laws and regulations and other binding obligations or provisions applicable to the Company, the Company may make a loan to the Warrantholder with respect to the exercise of the Warrant, including the payment by the Warrantholder of any or all federal, state and local income or other taxes due in connection with any exercise. The interest on such loan shall be the Company's cost of money plus an additional 0.5% at the time the loan is made and such loan shall be made with recourse against the Warrantholder. The Compensation Committee shall have the full authority to determine any other terms and provisions of such a loan.

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 20% of the underlying shares from and after 9:00 A.M. New York City time on October 27, 1999 (the "Initial Exercise Date"); (ii) 20% of the underlying shares on October 27, 2000 (the "Second Exercise Date"); (iii) 20% of the underlying shares on October 27, 2001 (the "Third 2 Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27, 2008 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). 3 (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by: (i) surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 3232 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M. on the Expiration Date (or 5:00 P.M. on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (ii) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company, subject to Section 1.5 herein) and (iii) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or, if permitted by subsection 1.5 and in accordance with the provisions thereof, such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining 4 Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares.

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 2050% of the underlying shares from and after 9:00 A.M. New York City time on October 27March 31, 1999 1997 (the "Initial Exercise Date"); (ii) 20and the remaining 50% of the underlying shares on October 27January 26, 2000 1998 (the "Second Exercise Date"); (iii) 20% of , the underlying shares on October 27Initial Exercise Date or the Second Exercise Date, 2001 as applicable (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") and to and including 5:00 P.M. New York City time on October 27March 31, 2008 2002 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by (a) surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 3232 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M. on the Expiration Date (or 5:00 P.M. on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (b) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company, subject to Section 1.5 herein) and (c) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The Common Stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or, if permitted by subsection 1.5 and in accordance with the provisions thereof, such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares.

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 20% of the underlying shares from and after 9:00 A.M. New York City time on October 27January 12, 1999 2001 (the "Initial First Exercise Date"); (ii) 20% of the underlying shares on October 27January 12, 2000 2002 (the "Second Exercise Date"); (iii) 20% of the underlying shares on October 27January 12, 2001 2003 (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27January 12, 2002 2004 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27January 12, 2003 2005 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27January 12, 2008 2010 (the "Expiration Date"). The Initial Each of the First Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred toto from time to time, as applicable, as the "Exercise Date" and collectively from time to time as the "Exercise Dates")." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any Any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the The individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the The stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) The stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (I.E., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by: (i) Surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 0000 XxXxxxxx Avenue, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M. on the Expiration Date (or 5:00 P.M. on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (ii) Delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company, subject to subsection 1.5 herein) and (iii) Such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The stock certificates so delivered shall be in denominations of at least one thousand (1,000) shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or, if permitted by subsection 1.5 and in accordance with the provisions thereof, such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares.

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 2050% of the underlying shares from and after 9:00 A.M. New York City time on October 27March 31, 1999 1997 (the "Initial Exercise Date"); (ii) 20and the remaining 50% of the underlying shares on October 27January 26, 2000 1998 (the "Second Exercise Date"); (iii) 20% of , the underlying shares on October 27Initial Exercise Date or the Second Exercise Date, 2001 as applicable (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") and to and including 5:00 P.M. New York City time on October 27March 31, 2008 2002 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by (a) surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 3232 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M. on the Expiration Date (or 5:00 P.M. on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (b) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company, subject to Section 1.5 herein) and (c) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The Common Stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or, if permitted by subsection 1.5 and in accordance with the provisions thereof, such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares. (c) With the consent of the Compensation Committee, and subject at all times to, and only to the extent, if any, permitted under and in accordance with, laws and regulations and other binding obligations or provisions applicable to the Company, the Company may make a loan to the Warrantholder with respect to the exercise of the Warrant, including the payment by the Warrantholder of any or all federal, state and local income or other taxes due in connection with any exercise. The interest on such loan shall be the Company's cost of money plus an additional .5% at the time the loan is made and such loan shall be made with recourse against the Warrantholder. The Compensation Committee shall have the full authority to determine any other terms and provisions of such a loan.

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 2050% of the underlying shares from and after 9:00 A.M. New York City time on October 27, 1999 [2 years from closing of the initial public offering of shares offered to the public pursuant to Registration Statement 33-98608 (the "Initial Public Offering")] (the "Initial Exercise Date"); (ii) 20and the remaining 50% of the underlying shares on October 27, 2000 [3 years from closing of the Initial Public Offering (the "Second Exercise Date"); (iii) 20% of , the underlying shares on October 27Initial Exercise Date or the Second Exercise Date, 2001 as applicable (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") and to and including 5:00 P.M. New York City time on October 27, 2008 [5 years from closing of the Initial Exercise Date] (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of outstanding voting securities of the Company immediately (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by (a) surrender of this Warrant, accompanied by the Exercise Form annexed hereto (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 2911 Xxxxxx Xxxxx Xxxxxxxxx, Xxxxx 000, Xxxxxx, Xxxxx 00000 (xx such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M. on the Expiration Date (or 5:00 P.M. on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (b) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form and (c) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder as promptly as practicable, and in any event within 10 business days, thereafter. The stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or, if permitted by subsection 1.5 and in accordance with the provisions thereof, such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares.

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 20% of the underlying shares from and after 9:00 A.M. New York City time on October 27, 1999 (the "Initial Exercise Date"); (ii) 20% of the underlying shares on October 27, 2000 (the "Second Exercise Date"); (iii) 20% of the underlying shares on October 27, 2001 (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27, 2008 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" the "Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by the

Duration and Exercise of Warrant. (a) This Warrant may be exercised as to purchase (i) 2025% of the underlying shares from and after 9:00 A.M. New York City time on October 27May 19, 1999 2001 (the "Initial Exercise Date"); (ii) 20and the remaining 75% of the underlying shares on October 27May 19, 2000 2002 (the "Second Exercise Date"); (iii) 20% of . The Initial Exercise Date or the underlying shares on October 27Second Exercise Date, 2001 (as applicable, is hereinafter referred to as the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27. This Warrant expires at 5:00 P.M., 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27May 19, 2008 2009 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of the outstanding voting securitiessecurities of the Company, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of the outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by (a) surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 3232 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M., New York City time, on the Expiration Date (or 5:00 P.M., New York City time, on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (b) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company) and (c) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares. (c) With the consent of the Compensation Committee, and subject at all times to, and only to the extent, if any, permitted under and in accordance with, laws and regulations and other binding obligations or provisions applicable to the Company, the Company may make a loan to the Warrantholder with respect to the exercise of the Warrant, including the payment by the Warrantholder of any or all federal, state and local income or other taxes due in connection with any exercise. The interest on such loan shall be the Company's cost of money plus an additional 0.5% at the time the loan is made and such loan shall be made with recourse against the Warrantholder. The Compensation Committee shall have the full authority to determine any other terms and provisions of such a loan.

Duration and Exercise of Warrant. (a) This Warrant may be exercised as to purchase (i) 2025% of the underlying shares from and after 9:00 A.M. New York City time on October 27May 19, 1999 2001 (the "Initial Exercise Date"); (ii) 20and the remaining 75% of the underlying shares on October 27May 19, 2000 2002 (the "Second Exercise Date"); (iii) 20% of . The Initial Exercise Date or the underlying shares on October 27Second Exercise Date, 2001 (as applicable, is hereinafter referred to as the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27. This Warrant expires at 5:00 P.M., 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") to and including 5:00 P.M. New York City time on October 27May 19, 2008 2009 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" the "Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of the outstanding voting securitiessecurities of the Company, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of the outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by (a) surrender of this Warrant, accompanied by either the Exercise Form annexed hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 3232 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M., New York City time, on the Expiration Date (or 5:00 P.M., New York City time, on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (b) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company) and (c) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares. (c) With the consent of the Compensation Committee, and subject at all times to, and only to the extent, if any, permitted under and in accordance with, laws and regulations and other binding obligations or provisions applicable to the Company, the Company may make a loan to the Warrantholder with respect to the exercise of the Warrant, including the payment by the Warrantholder of any or all federal, state and local income or other taxes due in connection with any exercise. The interest on such loan shall be the Company's cost of money plus an additional 0.5% at the time the loan is made and such loan shall be made with recourse against the Warrantholder. The Compensation Committee shall have the full authority to determine any other terms and provisions of such a loan.

Duration and Exercise of Warrant. (a) This Warrant may be exercised to purchase (i) 2050% of the underlying shares from and after 9:00 A.M. New York City time on October 27May 21, 1999 1997 (the "Initial Exercise Date"); (ii) 20and the remaining 50% of the underlying shares on October 27May 21, 2000 1998 (the "Second Exercise Date"); (iii) 20% of , the underlying shares on October 27Initial Exercise Date or the Second Exercise Date, 2001 as applicable (the "Third Exercise Date"); (iv) 20% of the underlying shares on October 27, 2002 (the "Fourth Exercise Date"); and (v) 20% of the underlying shares on October 27, 2003 (the "Fifth Exercise Date") and to and including 5:00 P.M. New York City time on October 27May 21, 2008 2002 (the "Expiration Date"). The Initial Exercise Date, the Second Exercise Date, the Third Exercise Date, the Fourth Exercise Date and the Fifth Exercise Date are hereinafter referred to, as applicable, as the "Exercise Date." In addition, in the event of a Change in Control of the Company, the right to exercise 100% of the underlying shares shall immediately vest. A "Change in Control" shall be deemed to have occurred if: (i) any person, other than the Company or an employee benefit plan of the Company, acquires directly or indirectly the Beneficial Ownership (as defined in Section 13(d) of the Securities and Exchange Act of 1934, as amended (the" the "Exchange Act")) of any voting security of the Company and immediately after such acquisition such Person is, directly or indirectly, the Beneficial Owner of voting securities representing 50% or more of the total voting power of all of the then-outstanding voting securities of the Company; (ii) the individuals (A) who, as of the closing date of the Initial Public Offering, constitute the Board (the "Original Directors") or (B) who thereafter are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors then still in office (such directors becoming "Additional Original Directors" immediately following their election) or (C) who are elected to the Board and whose election, or nomination for election, to the Board was approved by a vote of at least two-thirds (2/3) of the Original Directors and Additional Original Directors then still in office (such directors also becoming "Additional Original Directors" immediately following their election) (such individuals being the "Continuing Directors"), cease for any reason to constitute a majority of the members of the Board; (iii) the stockholders of the Company shall approve a merger, consolidation, recapitalization, or reorganization of the Company, a reverse stock split of outstanding voting securities, or consummation of any such transaction if stockholder approval is not sought or obtained, other than any such transaction which would result in at least 75% of the total voting power represented by thethe voting securities of the surviving entity outstanding immediately after such transaction being Beneficially Owned by at least 75% of the holders of outstanding voting securities of the Company immediately prior to the transaction, with the voting power of each such continuing holder relative to other such continuing holders not substantially altered in the transaction; or (iv) the stockholders of the Company shall approve a plan of complete liquidation of the Company or an agreement for the sale or disposition by the Company of all or a substantial portion of the Company's assets (i.e., 50% or more of the total assets of the Company). (b) The rights represented by this Warrant may be exercised by the Warrantholder of record, in whole, or from time to time in part, by (a) surrender of this Warrant accompanied by either the Exercise Form attached hereto, or if the Warrantholder decides to exercise the Warrant pursuant to the broker-assisted cashless exercise program instituted by the Company, an applicable exercise form provided by the Company (the "Exercise Form") duly executed by the Warrantholder of record and specifying the number of Warrant Shares to be purchased, to the Company at the office of the Company located at 3232 XxXxxxxx Xxxxxx, Suite 900, Dallas, Texas 75204 (or such other office or agency of the Company as it may designate by notice to the Warrantholder at the address of such Warrantholder appearing on the books of the Company) during normal business hours on any day (a "Business Day") other than a Saturday, Sunday or a day on which the New York Stock Exchange is authorized to close or on which the Company is otherwise closed for business (a "Nonbusiness Day") on or after 9:00 A.M. New York City time on the Exercise Date but not later than 5:00 P.M. on the Expiration Date (or 5:00 P.M. on the next succeeding Business Day, if the Expiration Date is a Nonbusiness Day), (b) delivery of payment to the Company in cash or by certified or official bank check in New York Clearing House Funds, of the Exercise Price for the number of Warrant Shares specified in the Exercise Form (such payment may be made by the Warrantholder directly or by a designated broker pursuant to the broker-assisted cashless exercise program instituted by the Company, subject to Section 1.5 herein) and (c) such documentation as to the identity and authority of the Warrantholder as the Company may reasonably request. Such Warrant Shares shall be deemed by the Company to be issued to the Warrantholder as the record holder of such Warrant Shares as of the close of business on the date on which this Warrant shall have been surrendered and payment made for the Warrant Shares as aforesaid. Certificates for the Warrant Shares specified in the Exercise Form shall be delivered to the Warrantholder (or designated broker, as the case may be) as promptly as practicable, and in any event within 10 business days, thereafter. The Common Stock certificates so delivered shall be in denominations of at least 1,000 shares each or such other denomination as may be specified by the Warrantholder and agreed upon by the Company, and shall be issued in the name of the Warrantholder or, if permitted by subsection 1.5 and in accordance with the provisions thereof, such other name as shall be designated in the Exercise Form. If this Warrant shall have been exercised only in part, the Company shall, at the time of delivery of the certificates for the Warrant Shares, deliver to the Warrantholder (or designated broker, as the case may be) a new Warrant evidencing the rights to purchase the remaining Warrant Shares, which new Warrant shall in all other respects be identical with this Warrant. No adjustments or payments shall be made on or in respect of Warrant Shares issuable on the exercise of this Warrant for any cash dividends paid or payable to holders of record of Common Stock prior to the date as of which the Warrantholder shall be deemed to be the record holder of such Warrant Shares. (c) With the consent of the Compensation Committee, and subject at all times to, and only to the extent, if any, permitted under and in accordance with, laws and regulations and other binding obligations or provisions applicable to the Company, the Company may make a loan to the Warrantholder with respect to the exercise of the Warrant, including the payment by the Warrantholder of any or all federal, state and local income or other taxes due in connection with any exercise. The interest on such loan shall be the Company's cost of money plus an additional .5% at the time the loan is made and such loan shall be made with recourse against the Warrantholder. The Compensation Committee shall have the full authority to determine any other terms and provisions of such a loan.