Joe made an offer to sell his car to Harry, promising to keep the offer open for a week. However, he changed his mind, sold the car to someone else, and phoned Harry to inform him that he was withdrawing the offer because he had sold the car to someone else. Harry was angry and said that he wanted the car and was going to hold Joe to his promise to hold the offer open for a week. He sued for breach of contract. Will he win? Explain.