Afra wrote to Noor asking him if he was interested in buying his car. In his letter, which arrived on Tuesday, Afra asked Noor to 'let him know by next Saturday'. On Thursday Noor replied accepting the proposal through post but at 6pm on Friday he changed his mind and telephoned Afra. Afra wasn't there but his telephone answering machine recorded Noor's message stating that he wished to withdraw his acceptance. On Monday Afra opened Noor's letter, which arrived that morning, and then played back the message on the machine. Advice Afra if he has a binding contract with Noor?