Exhibit A JOINT FILING UNDERTAKINGJoint Filing Undertaking • May 18th, 2007 • Yorktown Avenue Capital, LLC • Water, sewer, pipeline, comm & power line construction
The undersigned, being duly authorized thereunto, hereby execute this agreement as an exhibit to this Schedule 13D to evidence the agreement of the below-named parties, in accordance with the rules promulgated pursuant to the Securities Exchange Act of 1934, to file this Schedule jointly on behalf of each such party.
