If an item or items on a purchase order have been received on Sage by accident (e.g. by using the receive all button when not all items on the PO have actually been received or by selecting the wrong PO number and clicking receive deliveries) the ability to undo this/these transaction(s) and reinstate the items as outstanding on the purchase order would be useful. At the moment the only way to correct this type of error is to adjust the stock out on the products list and then make a new purchase order.