Real estate commissions become due and payable when the broker has produced a purchaser with whom the owner entered into a valid and enforceable contract. Dennis v. Walters, 123 I11. App. 93.

Where a broker has procured a purchaser acceptable to the seller, and an enforceable written contract is made between them, the broker's right to commissions is not dependent on the purchaser's ability to pay for the land. Hamburger v. Thomas (Tex. Civ. App. '09), 118 S. W. 770; Hudson P. Ross Co. v. Goodale, Perry & Wright, 169 N. Y. Sup. 446; McCartney v. Shaves, 188 P. 663, - Okl. Sup. - . Compare Sec. 464. See also Secs. 484, 504.