EXHIBIT A JOINT FILING AGREEMENT

EXHIBIT A
JOINT FILING AGREEMENT

SCHEDULE 13G
JOINT FILING AGREEMENT

     This Agreement is dated as of January 22, 2009 by and among Mercury Fund VII, Ltd. (“Mercury VII”), Mercury Fund VIII, Ltd., (“Mercury VIII”), Mercury Ventures II, Ltd. (“Mercury Ventures II”), Mercury Management, L.L.C. (“Mercury Management”) and Xxxxx X. Xxxx (“Xx. Xxxx”).

     WHEREAS, pursuant to paragraph (k)(1) of Rule 13d-1 promulgated under Section 13d(1) of the Securities Exchange Act of 1934, as amended (the “Act”), the parties hereto have decided to satisfy their filing obligations under the Act by a single joint filing.

     NOW, THEREFORE, the undersigned do hereby agree as follows:

     1. The Schedule 13G (the “Schedule 13G”) with respect to TRX, Inc., a Georgia corporation, to which this Agreement is attached as Exhibit A is filed on behalf of Mercury VII, Mercury VIII, Mercury Ventures II, Mercury Management and Xx. Xxxx. Mercury VII, Mercury VIII, Mercury Ventures II and Mercury Management hereby authorize Xx. Xxxx to file the Schedule 13G on their behalf.

     2. Each of Mercury VII, Mercury VIII, Mercury Ventures II, Mercury Management and Xx. Xxxx is responsible for the completeness and accuracy of the information concerning such person or entity contained therein; provided that each person or entity is not responsible for the completeness or accuracy of the information concerning any other person or entity making such filing.

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     IN WITNESS WHEREOF, the undersigned hereunto set their hands as of the date first above written.

		MERCURY FUND VII, LTD.
		By:		MERCURY VENTURES II, LTD.
				General Partner
				By:		MERCURY MANAGEMENT, L.L.C.
						General Partner
						By:		/s/ Xxxxx X. Xxxx
						Name:		Xxxxx X. Xxxx
						Title:		Manager
		MERCURY FUND VIII, LTD.
		By:		MERCURY VENTURES II, LTD.
				General Partner
				By:		MERCURY MANAGEMENT, L.L.C.
						General Partner
						By:		/s/ Xxxxx X. Xxxx
						Name:		Xxxxx X. Xxxx
						Title:		Manager
		MERCURY VENTURES II, LTD.
		By:		MERCURY MANAGEMENT, L.L.C.
				General Partner
				By:		/s/ Xxxxx X. Xxxx
				Name:		Xxxxx X. Xxxx
				Title:		Manager
		MERCURY MANAGEMENT, L.L.C.
		By:		/s/ Xxxxx X. Xxxx
		Name:		Xxxxx X. Xxxx
		Title:		Manager
		/s/ Xxxxx X. Xxxx
		Name:		Xxxxx X. Xxxx