I have a price list which i will use to quote prices. I want to set a line to not appear in printing if the item in it is not used. eg:

desc unit price qty price
a 20 2 40
b 40 0 0
c 25 1 25

subtotal 65
tax 9.1
total 74.1

Item B line should not appear in the print, as the quantity is zero.