This Pledge Agreement and each Pledge Joinder Agreement, together with the Credit Agreement and o ther Loan Documents, constitute and express the entire understanding between the parties hereto with respect to the subje ct matter hereof, and supersede all prior negotiations, agreements and understandings, inducements, commitments or conditions, express or implied, oral or written, except as herein contained.  The express terms hereof and of the Pledge Joinder Agreements control and supersede any course of performance or usage of the trade inconsistent with any of the terms hereof and thereof.  Neither this Pledge Agreement nor any Pledge Joinder Agreement nor any portion or provision hereof or thereof may be changed, altered, modified, supplemented, discharged, canceled, terminated, or amended orally or in any manner other than as provided in the Credit Agreement.