No waiver by a Party of any right hereunder or failure to enforce a breach of any of the terms of this Agreement will be valid unless in writing and signed by an authorized representative of each Party hereto.  Failure by either Party to enforce any rights under this Agreement will not be construed as a waiver of such rights, nor will a waiver by either Party in one or more instances be construed as constituting a continuing waiver or as a waiver in other instances.