You are the audit senior assigned to the audit of Speedy Ltd, a motor vehicle spares company. You obtain an understanding of the ordering function within the revenue and receipts cycle at Speedy Ltd. All orders are captured by the debtors' clerk, who will input the order into the revenue system by creating an internal sales order and capturing the order details. Which one of the following programme controls should be implemented to ensure that the order quantity is accurate before processing the order?