Invetory Returns.

Title

Invetory Returns.

Post

Alright i been working with the Invoice starter template been working for me so far made few adjustments here and there but its working fine. I got a inventory Out button so when i press it, it takes what ever in the line items from the inventory stock. now i run a rental company and i want to set this up so i can setup another button that lets me "return" items back. pretty much i want a button with a script that does the opposite instead of minusing i want it to add to the amount of stock at hand. any help would be apreciated.