EXHIBIT A JOINT FILING AGREEMENT

EXHIBIT A

JOINT FILING AGREEMENT

The undersigned acknowledge and agree that the foregoing statement on Schedule 13D/A is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D/A shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the other, except to the extent that he or it knows or has reason to believe that such information is not accurate.

Dated: February 15, 2007

CAMDEN PARTNERS STRATEGIC FUND III, L.P.
By:		Camden Partners Strategic III, LLC,
		its General Partner
By:		Camden Partners Strategic Manager, LLC,
		its Managing Member
By:		/s/ Xxxxxx X. Xxxxxx
Name:		Xxxxxx X. Xxxxxx
Title:		Managing Member
CAMDEN PARTNERS STRATEGIC FUND III-A, L.P.
By:		Camden Partners Strategic III, LLC,
		its General Partner
By:		Camden Partners Strategic Manager, LLC,
		its Managing Member
By:		/s/ Xxxxxx X. Xxxxxx
Name:		Xxxxxx X. Xxxxxx
Title:		Managing Member

CAMDEN PARTNERS STRATEGIC III, LLC
By:		Camden Partners Strategic Manager, LLC,
		its Managing Member
By:		/s/ Xxxxxx X. Xxxxxx
Name:		Xxxxxx X. Xxxxxx
Title:		Managing Member
CAMDEN PARTNERS STRATEGIC MANAGER, LLC,
By:		/s/ Xxxxxx X. Xxxxxx
Name:		Xxxxxx X. Xxxxxx
Title:		Managing Member

/s/ Xxxxxx X. Xxxxxx

Xxxxxx X. Xxxxxx, an Individual

/s/ Xxxxxx X. Xxxxxx, Attorney-in-Fact

Xxxxxxx X. Xxxxxxxx, an Individual

/s/ Xxxxxx X. Xxxxxx, Attorney-in-Fact

Xxxxx X. Xxxxxxx, an Individual

/s/ Xxxxxx X. Xxxxxx, Attorney-in-Fact

Xxxxxxx X. Berkeley, an Individual