Patrice and cornell are completing a sales contract with mary, their agent. the sales contract used at mary's brokerage is preprinted. mary, as a senior agent, has the authority to waive one of the brokerage's fees. the fee is explained and preprinted on the contract. mary simply crosses it out, writes "waived" and both parties initial. which overrules the other? the preprinted or handwritten portions of the contract?