MIGO PROBLEM in the Good Receipt with reference to purchase order

Hello Everybody.

i m getting one problem with reference to MIGO tcode.

Might be anyone notice or not but i want to share with you.

in MIGO selected goods receipt then beside it ask for the different actions.

I use the purchase order no.

suppose i given po no 1

enter

now it will display the details of that po number (1) but at the same time po number field is again in the input mode and you can give more po number .

suppose now i have given po no 2.

enter

Then in same gr we will be having the item details of both po number( 1 & 2) .

This is my problem .I want to make restriction that in single gr it should take only one po number not more than that ,after giving one po ,it should make that field in display mode.

How to do that please guide me .

I will be grateful to you.

Thanks a lot