Exhibit 99.4

JOINT FILING AGREEMENT

PURSUANT TO RULE 13d-1(k)(1)

The undersigned acknowledge and agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D 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 it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that it knows or has reason to believe that such information is inaccurate. This Agreement may be executed in any number of counterparts and all of such counterparts taken together shall constitute one and the same instrument.

Dated: March 30, 2010

THIRD POINT LLC

By: Daniel S. Loeb, Chief Executive Officer

By: /s/ Joshua L. Targoff

Name: Joshua L. Targoff

Title: Attorney-in-Fact

DANIEL S. LOEB

By: /s/ Joshua L. Targoff

Name: Joshua L. Targoff

Title: Attorney-in-Fact

THIRD POINT OFFSHORE MASTER FUND, L.P.

By: Third Point Advisors II L.L.C., its general

partner

By: Daniel S. Loeb, Managing Director

By: /s/ Joshua L. Targoff

Name: Joshua L. Targoff

Title: Attorney-in-Fact

THIRD POINT ADVISORS II L.L.C.

By: Daniel S. Loeb, Managing Director

By: /s/ Joshua L. Targoff

Name: Joshua L. Targoff

Title: Attorney-in-Fact