John has a car that breaks down a lot. One day, John was driving his car with his brother Goerge. During the drive, John's car broken down, again. John was angry and said to his brother Georgie:"This car is a piece of junk. I am sick and tired of it breaking down all the time. I will sell it to you for $1,000". George replies to John: "sure, I will buy it from you for $1,000. Bring it to my house tomorrow and I will p-ay you the $1000 then". The following day, John brings the car over to Goerge's house and asks George for the 1000, George tells John that he has thought about it since yesterday and that George no longer wants top buy John's car. George does not believe that he and John have a valid contract.

DO THEY? YES OR NO? WHY?