setup, settings, receivables, linked accounts

 deposits and prepaid orders should be linked to a liability account (prepaid sales/deposits)

create a receipt, which has a list of file, edit, view, receipt

click receipt, and check 'enter deposits'

this will give you an 'deposit amount' field to record the prepayment

once you've create the invoice (at a future date), create receipt will allow you to applied this deposit

Hi Roger.  Thank you for your input.  I tried what you suggested, and it worked until I got to the invoice part.  In the invoice, I couldn't use prepaid sales/deposit account (to offset the original credit to that account), when I created the receipt.  The program wouldn't let me.  It also won't let me do a general journal entry with that account.  I don't understand why.  Did I  miss something?  

the prepaid amount is applied to the invoice using 'create receipt' - you're paying the invoice, not from the bank, but from the prepaid 'red' amount

You don't necessarily want to 'offset' the invoice with the credit. Ideally the invoice will always show the full amount with the proper taxes etc. You could make a note in the description part of the invoice that a deposit of xxx.xx dated MMMDDYY has been received but the amounts do not change.

Then the receipt portion can have the 'deposit' amount applied to the invoice making it a zero receipt.

Pmt to pay on Invoice 1000.00

Deposit 1000.00

Equals a nil receipt.

Then print off a statement which shows the original invoice, the deposit applied to the invoice and the balance of invoice outstanding.