In a broker's action for commission involving issue whether owners had by express contract agreed to pay a certain commission, telegram by prospective purchaser to owners stating commission wanted by broker; held competent, in view of undisputed evidence that broker had not advised such prospective purchaser as to commission he was expecting, to establish amount of commission that owner had in mind, and that minds of parties never met on amount claimed by broker. Parker v. Lindsey, 176 N. W. 1018, - S. D. Sup. - .