When a sales order is created or changed, I have certain customers who need to have their part number (VBAP-KDMAT) and line number (VBAP-POSEX) carried all the way through billing for EDI purposes. I have written some code in sales order exit MV45AFZB to display a popup message if either piece of information is missing. Where I am struggling is how to get the system to not advance to the next line until these pieces of information are populated. I have tried putting code in MF45AIZZ, and MV45AOZZ,where the screen name equals VBAP-KDMAT or VBAP-POSEX to set the cursor in these fields; I have tried playing with SCREEN-INPUT and SCREEN-REQUIRED but I am not having much luck. Has anyone done anything like this before, or can you point me in the right direction?