Syed offers to sell his bike to Judy for $100. She says she wants a week to decide and Syed agrees. The next day he changes his mind and rings Judy...

Syed offers to sell his bike to Judy for $100. She says she wants a week to decide and Syed agrees. The next day he changes his mind and rings Judy to say that the bike is not for sale. Judy then says "I accept your offer to sell me the bike and I am accepting within the week you said you would allow so we have a contract." Is there a contract in this situation? Explain your answer