Where, in an action for a division of a broker's commissions, the contract between the parties provided that if plaintiff would "assist" in obtaining a purchaser he should be entitled to one-half the commissions earned, an instruction that unless the person claiming the commissions find such purchaser and communicate the fact to the other party at the time, he can not recover, was properly refused. McCleary v. Willis, 35 Wash. 676, 77 P. 1073. See also Sec. 799.