In an action for a broker's commissions, an instruction that the sale contract contained the terms of the sale and plaintiff's authority, and that he had no right to sell the land on any other terms, and if he changed the contract, without defendant's knowledge or consent, by striking out the rate of interest to be paid, it was a material alteration, and would not bind defendant, nor entitle plaintiff to recover his commissions, was not objectionable, in that it omitted to charge that, if plaintiff made the change in good faith, believing that it was in accordance with the understanding of the parties, there was no fraud. Robertson v. Vasey, 125 Iowa, 526, 101 N. W. 271. See also Sec. 969. Compare Sec. 485.