Russell (D1) bought a used tractor from McGinnis Equipment Co. (P). D1 failed to make the first installment payment on the tractor. D1 met with D who agreed to help with the payments. Some of D's checks were returned for insufficient funds. P threatened to repossess the tractor and D orally promised to pay off the delinquent installments. D never did pay the installments as promised. P finally repossessed the tractor. P sued D and D1. P won a default against D1. D was found liable for the entire amount owed. D appealed.