Exhibit A JOINT FILING UNDERTAKINGJoint Filing Undertaking • May 11th, 2007 • Yorktown Avenue Capital, LLC • Retail-building materials, hardware, garden supply
Contract Type FiledMay 11th, 2007 Company IndustryThe 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.