"Where, in an action by a broker for commissions for procuring a purchaser of land, the evidence showed that the sale was consummated on the terms proposed by the owner, it was not error to omit to charge that the proof must show that the purchaser procured was able, ready and willing to complete the purchase on the terms prescribed. Lewis v. Susmilch, 130 Iowa, 203, 106 S. W. 624.