y Texas Continental's dishonored checks enforceable? If not, what would have been required in the nature of a writing to make the promise enforceable?...

Was Moore's oral promise to pay Texas Continental's dishonored checks enforceable? If not, what would have been required in the nature of a writing to make the promise enforceable? Suppose there had been a written agreement between Moore and the bank: Would the bank have been able to enforce an oral promise made by Moore that was not stated in the written contract? Would it be ethical of Moore not to pay the bank?