Any term or provision of this Agreement may be waived, or the time for its performance may be extended, by the party or parties entitled to the benefit thereof.  Any such waiver shall be validly and sufficiently authorized for the purposes of this Agreement if, as to any party, it is authorized in writing by an authorized representative of Seller or by an authorized representative of Buyer, as the case may be.  The failure of any party hereto to enforce at any time any provision of this Agreement shall not be construed to be a waiver of such provision, nor in any way to affect the validity of this Agreement or any part hereof or the right of any party thereafter to enforce each and every such provision.  No waiver of any breach of this Agreement shall be held to constitute a waiver of any other or subsequent breach.