C. & A. Construction Co. (CACC) (defendant) and Benning Constriction Co. (Benning) (plaintiff) were subcontractors on a sewer line installation project. Their contract stated the following: “It is further agreed that [Benning] will receive $20,000 for supervision which will be added to the actual cost figure.” Benning’s president was to conduct the supervision of the project. Benning was permitted to present evidence of a verbal agreement to pay its president a salary and living expenses—in addition to the $20,000—while he supervised. The trial court awarded Benning $20,000 for supervision plus $18,600 for salary and living expenses while its president was engaged in such supervision. CACC appealed as to the amount of this supervision award.