In order to take advantage of a variance between the allegations of a petition and the proof, defendant must make objection in the trial court to the introduction of evidence on that ground and show by affidavit, in what respect he has been misled thereby. Fisher, etc., R. E. Co. v. Staed R. Co., 159 Mo. 562, 62 S. W. 443; Gregg v. Loomis, 22 Neb. 174, 34 N. W. 355; Thompson v. Sargent, 134 P. 7, 66 Or. 354.