Exhibit 99.1
EXHIBIT A
JOINT FILING UNDERTAKING
The undersigned, being authorized thereunto, hereby execute this agreement as an exhibit to this Amendment No. 1 to the Schedule 13G to evidence the agreement of the below-named parties, in accordance with rules promulgated pursuant to the Securities Exchange Act of 1934, to file this Schedule, as it may be amended, jointly on behalf of each of such parties.
| Dated: February 13, 2013 | WaldenVC, LLC | |||||
| By: | /s/ Lawrence Marcus | |||||
| Name: Lawrence Marcus | ||||||
| Title: Managing Member | ||||||
| WaldenVC II, L.P. | ||||||
| By: | /s/ Lawrence Marcus | |||||
| Name: Lawrence Marcus | ||||||
| Title: Managing Member | ||||||
| WaldenVC III, LLC | ||||||
| By: | /s/ Lawrence Marcus | |||||
| Name: Lawrence Marcus | ||||||
| Title: Managing Member | ||||||
| WaldenVC SPK, LLC | ||||||
| By: | /s/ Lawrence Marcus | |||||
| Name: Lawrence Marcus | ||||||
| Title: Managing Member | ||||||