EXHIBIT 2
JOINT FILING AGREEMENT
The undersigned hereby agree to the joint filing of the Schedule 13D to which this Agreement is attached.
Dated: September 13, 2012
DISCOVERY GROUP I, LLC | |||
By: | /s/ Michael R. Murphy* | ||
Michael R. Murphy Managing Member | |||
Daniel J. Donoghue* | |||
Daniel J. Donoghue* | |||
Michael R. Murphy* | |||
Michael R. Murphy | |||
By: | /s/ Mark Buckley | ||
Mark Buckley | |||
Attorney-in-Fact for Daniel J. Donoghue | |||
Attorney-in-Fact for Michael R. Murphy |