Your audit client, Madison, Inc., has a computerized accounts receivable system. There are two master files, a customer data file and an unpaid invoice file. The customer data file contains the customer's name, billing address, shipping address, identification number, phone number, purchase and cash payment history, and credit limit. For each unpaid invoice, the second file contains the customer's identification number, invoice number and date, date of shipment, method of shipment, credit terms, and gross invoice amount. Discuss how GAS could be used to aid in the audit of Madison's accounts receivable.