Hey all - Trying to wrap up my first workflow. Added a discount item for Free Shipping. What I want is to populate this discount amount from the shipping cost field when an invoice is generated and contains that discount item. Problem is, the amount populating from the shipping cost field is positive when I need it to be negative. I can't figure out how to accomplish this through the Formula function. Any tips for the formula field syntax for something like this?

why are you going through all this work to make the shipping free? Couldnt you update or create a shipping item to do this?

There's a lot to it. For starters, it's not going to apply to every transaction. Our shipping label generator (OZlink/UPS Worldship) also overwrites any previously entered shipping cost amount back onto the IF after the label is generated. So to prevent my shipping department from having to manage it, I thought I'd create a simple workflow to back it out of the invoice via a discount if the order qualified for free shipping. Once that's in place I can build other workflows around it to automate the order entry process more.