American Bank loaned Koplik $50,000 to buy equipment for a restaurant about to be opened by Casual Citchen Corp. The loan was not repaid, and Fast Foods, Inc., bought out the interest of Casual Citchen. As part of the transaction, Fast Foods agreed to pay the debt owed to American Bank, and the parties agreed to a new schedule of payments to be made by Fast Foods. Fast Foods did not make the payments, and American Bank sued Koplik. He contended that his obligation to repay $50,000 had been discharged by the execution of the agreement providing for the payment of the debt by Fast Foods. Was this defense valid? [American Bank & Trust Co. v Koplik, 451 NYS2d 426 (App Div)]