We record prepayments directly on our orders using the Amount Received field (Sales Payment Entry window).  This works perfectly when the payment is cash or credit.  However, sometimes we need to apply part of the payment from a credit on the customer account.  I don't believe there is a way to do this pre-invoice, however, I'm wondering if I can at least use the COD Amount field on the Sales Payment Entry window to track what still needs to be applied to the order after the invoice is posted.  From what I can tell, entering an amount in the COD Amount field does nothing.  It seems to be just a place holder.  Is that accurate?  If I apply a partial cash payment, put the remaining in COD, invoice, post, and then apply the remaining amount due from credit - will that work?  Or will having an amount in COD come back to bite me somewhere down the road?