Void Sale 
Void Sales Completed "Sales" transactions may be voided with this function. This function should only be used if the "Sale" has been completed but needs to be reversed for whatever reason. All items will be returned to inventory and other credit card adjustments automatically reversed. If the integrated credit card payment server is active in your system, any previously charged amounts will also be reversed Only the original transaction numbers from the sales receipt is needed to initiate the void sale.