Forum Post: Applying discounts to a current bill.

I'm using Timeslips by Sage 2008. We've been able to apply discounts to old bills easily, but we want to apply a discount to a current bill now -- i.e. one that has not yet gone out. Because Timeslips demands we apply discounts to a particular invoice and that invoice will not reflect changes made to it after its creation (such as applying a discount), I can't imagine how we're supposed to manage this. In this instance we have an invoice with $X of services and we want to cut 20% off of that.