How to lock a price on an invoice?
I have Inventory and Invoice FM11 databases that are connected through a portal. All the items are one of a kind, so I set up a portal in the invoice to grab all the info, each item on a new line in the portal. But, now I found an unforeseen issue: If the item is returned and resold at a different price (by changing the price in the Inventory page), it of course changes the price on the line item of the old invoice, changing its total. Bah.
How to I lock the price on the old invoice? I was thinking of using a look-up field, but it seems that field would have to be coming from the Inventory table, and could only have one value - either the old look-up and price, or the new.
Am I missing something basic here? Sorry - I have a very limited depth of FM understanding...
thanks! -- Don