Whether Output is Possible for fully deleted PO in R/3

Hi,

I have created a PO with two line items and created message output to send to the vendor. Now i have changed the PO by deleting two line items and able to save it but not output it. Im getting message update terminated when i go to output messages tab in PO. Whether is this standard SAP behaviour? It is not possible to output a fully deleted PO?

Thanks

Navin