We did an AP Processing demonstration for a client earlier this morning.  One of the questions that came up was if it was possible to do a countdown of the purchase order amount as individual invoices are being paid for that one PO.  An example would be, they have a PO for $100,000 but that amount is split into payments, so they will have maybe 12 different invoices against that one PO throughout a period of time.  They call this type of PO an “open PO”. 

The way they do it right now, is every time one of those invoices get paid per month, they put a post-it note on the PO with the new amount.  Is there a way the total amount field can change (countdown) every time one of those invoices are paid?