What are the conditions of a contract where the contract does not specify the amount of fees payable?

amount of fees to be paid, but rather left that for future determination or agreement. However, neither law nor equity requires that every term and condition of an agreement be set forth in the contract. (Hennefer v. Butcher (1986) 182 Cal.App.3d 492, 500-501, 227 Cal.Rptr. 318.) "The usual and reasonable conditions of such a contract are, in the contemplation of the parties, a part of their agreement." (King v. Stanley (1948) 32 Cal.2d 584, 588, 197 P.2d 321.) In the absence of express conditions, a court may look to custom and practice to determine incidental matters, so long as such matters do not alter or vary the terms of the agreement. (See id. at pp. 588-589, 197 P.2d 321.)