AGREEMENT OF JOINT FILING

                                    EXHIBIT A

                            AGREEMENT OF JOINT FILING

In accordance with Rule 13d-1(k) under the Act, the undersigned hereby agree to
the joint filing with the other persons signatory below of a statement on
Schedule 13D or any amendments thereto, with respect to the Common Stock, and
that this Agreement be included as an attachment to such filing.

This Agreement may be executed in any number of counterparts each of which shall
be deemed to be an original and all of which together shall be deemed to
constitute one and the same Agreement. IN WITNESS WHEREOF, the undersigned
hereby execute this Agreement on the 9th day of April, 2008.

                              /s/ Xxxxxx X. Xxxxxxxx
                              ---------------------------------
                              XXXXXX X. XXXXXXXX

                         THE CO-INVESTMENT FUND II, L.P.

                         By:  Co-Invest Management II, L.P, its General Partner

                         By:  Co-Invest II Capital Partners, Inc. its General
                              Partner

                         By:  /s/ Xxxxx Xxxxxxx
                              ---------------------------------
                              Xxxxx Xxxxxxx, Chief Financial Officer

                         CO-INVEST MANAGEMENT II, L.P.

                         By:  Co-Invest II Capital Partners, Inc., its General
                              Partner

                         By:  /s/ Xxxxx Xxxxxxx
                              ---------------------------------
                              Xxxxx Xxxxxxx, Chief Financial Officer

                         CO-INVEST II CAPITAL PARTNERS, INC.

                         By:  /s/ Xxxxx Xxxxxxx
                              ---------------------------------
                              Xxxxx Xxxxxxx, Chief Financial Officer