Remove Discount line from screen form

Remove Discount line from screen form

I have removed the Discount line on all sales orders and invoice templates but it still is available in the screen entry form. it sometimes gets used for deposits (yes is an error but humans are predictably unpredictable) because of its presence  and creates problems with the pricing and tax calculations. Is there a way to remove the line from the screen form?

Greg Aanes
2109 Queen Street
Bellingham WA USA