How to raise an exception in the badi

Question

Hi friends..I've got the badi to be used for my object.Badi workorder_confirm
requirement is " if data is entered in one field leaving a field emprty,it should give an error message saying "Field is mandatory". I can make use of ERROR_WITH_MESSAGE exception for the message to be generated..
but dont know the syntax of it..please provide me with the statement how the message needs to be raised

Answer 1

Looking at the BAdI Documentation it says this:
Note that in the methods, no system messages may be sent. The only      
exceptions are the AT_SAVE and AT_CANCEL_CHECK methods. Within these    
methods, a system message may be issued, but only if you trigger the    
exception ERROR_WITH_MESSAGE (for AT_SAVE method) or NOT_ALLOWED (for   
AT_CANCEL_CHECK method) at the same time.                                                                               
Note also, that within the methods the "commit work" instruction may not
be carried out because this would lead to incorrect data in the         
database.                                                               
So the only thing you can do is use:
RAISE ERROR_WITH_MESSAGE.