Scheck (D) unilaterally offered in writing to sell real estate to a specified prospective buyer and to pay Marchiondo (P), a real estate broker, a broker's commission. The offer set a six-day time limit for acceptance. D then revoked the offer in writing. P received D's revocation on the sixth day. Later that day, P obtained an acceptance from a prospective buyer. P sued D for breach of contract. The trial court dismissed the complaint and P appealed.