Where defendant denies that he agreed to pay plaintiff a commission for selling his property at a certain price as claimed by plaintiff, evidence of one to whom defendant had given an option prior to the alleged agreement that he was able and willing to pay said price without any deductions therefrom, was competent to disprove the contract. Dexter v. Collins, 21 Colo. 455, 42 P. 664; Border v. Isherwood, 120 Iowa, 677, 94 N. W. 1128; McDermott v. Mahoney, 119 Iowa, 470, 115 N. W. 32, 1.30 Iowa, 200; Lewis v. Susmilch, 130 Iowa, 203, 106 N. W. 624; Jennings v. Rooney, 183 Mass. 577, 67 N. E. 665; Childs v. Ptomey, 17 Mont. 502, 43 P. 714; Jackson v. Biggins, 70 N.

H. 637, 49 A. 574; Miller v. Irish, 3 Hun (N. Y.), 352, 67 Barb. 256, 5 Thomps. & C. 707, affirmed 63 N. Y. 652; Hodgkins v. Mead, 8 N. Y. S. 854; Dayton v. Ryerson, 13 How. Pr. (N. Y.) 281; Bertelson v. Hoffman, 35 Wash. 459, 77 P. 801; Going v. Cook, 1 Wash, 224, 23 P. 412; Indiana Fruit Co. v. Sandlin, 125 Ga. 222, 54 S. E. 65; Harvey v. Lindsay, 117 Mich. 267, 75 N. W. 627; Williams v. Nelson, 145 P. 39, 45 Utah, 255; Davis v. Keasy, 93 A. 335, 247 Pa. 303; Loving v. Kane, 180 I11. App. 614; Morrison v. Franck, 117 P. 308, 59 Or. 429; Justy v. Erro, 117 P. 575, 16 Cal. App. 519; Riggins v. Sass, 143 S. W. 689, - Tex. Civ. App. -; Silberkraus v. Winnie, 142 N. Y. Sup. 887, 158 App. Div. 50; Andrew v. Mace, 194 S. W. 598, - Tex. Civ. App. -; Smith v. Sharp R. E. Co., 77 S. 40, 200 Ala. 666; Cooper v. Newsom, 224 S. W. 568, - Tex. Civ. App. - .