User Exit to make Payment Term field non editable in item level .

Hi all,

User wants to make the Payment Term field in sales order as non editable and Payment terms is copied from Customer Master to Sales order.

I use user exit MV45AFZZ (USEREXIT_FIELD_MODIFICATION) to make Payment Term field non editable in header level.

I am not able to do it in item level. Pl help to to make Payment Term field non editable in item level.

Thanks,

sunil