Persons employed to sell certain lots of land at prices named in a written contract of employment, the lots to be sold only in the order enumerated in the contract, were not entitled to commissions for procuring a purchaser of lots not in their order, though the owner's refusal was not based on that ground. Stearns v. Jennings, 128 Wis. 379, 107 N. W. 327. See also Secs. 340, 840.