Perform in Script

Hi ABAPers,

I am customising standard Goods Receipt script form, in that i want to add Purchase Order date. In standard form PO number displayed already. Now i have exported the PO number as parameter using Perform statement in script, accordingly i designed a report program to hold subroutine to return PO date. But it is not working.

After activating scipt debugger on. i went step by step, at perform statement, even it is not calling the subroutine which created in report program.

How can i do?

Pls reply me. I want the answer immediately.

Yours,

S.GUNA