Stephen T. Colbert is under contract to speak at WSU graduation. On the day before he is to appear he tells the president, who signed the deal, that he cannot appear unless the university pays him $10,000 more than originally stated under contract. President Hopkins reluctantly agrees, but wisely bargains to get Colbert to agree to also give a lecture at the Raj Soin College of Business. Is the president's agreement to pay extra money enforceable?