Is possible to delete a PO after received goods...

thanks Joe, I think I can't void it as it said "This order cannot be cancelled because some of it has already been received.
The line item quantities may be modified to quantities more than already received. prices cannot be altered for lines that have already been received and quantities cannot be reduced below the quantity already received."

So I need to do both void the PO and adjust the items in inventory(negative adjustment)?

Many thanks Joe