Field Subledger for Creditor Prepayments

If you created a payment line of type 'Creditor' and selected a prepayment under subledger entries, it was not displayed in the Subledger field. This is because a prepayment does not have an invoice number. We have devised the following solution: for a prepayment, the Document field will now be shown, and for 'normal' open items, the Invoice Number field will be displayed.