How to enter a product return

**Assumptions: Selling screen is present.**
Step	Keys to press	Result
1		Use the arrow keys to highlight the line and quantity column on the selling screen.
2		Press the enter key to begin. The the quantity will highlight in yellow.
3	-1	Press the "-" key, (minus) followed by the quantity to return.
4		Press the enter key to complete the product return. The line should have a negative total.