button after you have entered an invoice number.Enter the paid invoice's invoice number or use the PopUp feature (F4) to search among all unpaid invoices.
To the right of this field you can preview the invoice by using the Preview button after you have entered an invoice number.
If you enter the customer code in the top portion of the window, you can load the current customer's unpaid invoices using the PopUp feature in the lower portion of the window.