Converting PO to PDF without using spool number

Hi,

Need to convert and download PO to PDF by standard method in SAP. Right now I am first creating spool request and then converting PO to PDF in SAP using program RSTXPDFT4 using spool number.

I need to do it in ME9F that when we press Output Message the system should ask whether to print the PO directly or to convert and download it in PDF format. We are using script forms for PO print. Please help.

Regards,