Make supplier site mandatory on autocreate PO

Hi All ,

We have noticed an issue with our PO Account generator on release 11.5.10  and need to ensure that all the users provide the supplier site details for proceeding to auto create the PO.  Can you please let me know how we can personalise the form to prevent users from proceeding to the next window without entering the supplier site details in the Auto Create Purchase Orders . The form is PO _POXBWVRP.

Thanks in advance

Samir