bapi => bapi_po_change

Hello Experts,

I'm using the BAPI bapi_po_change in my program to update the field delivery complete indicator in tthe database.

i'm passing the po number in the bapi. i want that if the PO number i'm passing is being edited by any other transaction code than this should be processed by bapi.

and for that particular po no. i have to show the message as ERROR in the ALV display i'm showing as a output of my program.

please help as early as possible.

helpful responses would be highly rewarded.

thanks,

Krishan Kumar.