Books & More sells hardcover and paperback books, music tapes, and CDs. It keeps a large stock of merchandise and orders new products often. The store may place an order for fast-selling items, such as a pop ular new CD, weekly. 

You recently noticed two invoices for three dozen CDs ordered from the same music wholesaler. The CDs ordered and the amounts on both invoices are identical. 

INSTRUCTIONS

1. Explain how you would determine whether the invoices are for two different orders or are duplicate invoices for one order.

2. Suggest steps to ensure that the company does not pay duplicate invoices.