A-One HVAC started selling annual maintenance agreements for $100 in January. This entitles the customer to two maintenance calls - one in May and one in October. A-One also performs maintenance calls by appointment for $75 per call. A-One had sold 50 agreements between January and April. No agreements were sold in May but they did make all the service calls as promised. They also made 20 "by appt" calls in May. What entries were made in May to record the maintenance revenue?