There is a FM 'L_TO_CREATE_DN' which is used in inbound idoc creation program .
Just after running this FM in the code , the idoc gives an error message.
I am checking through WE19.
I need to change the error message ,so I need to catch this message .
But as soon as I do a F6 on the FM the program gets executed and the output error message popsup.
How can I catch this message.