Query on User Exit for PO .............Urgent plz help

hi

Friends,

Here is my query on Po Posting

whenever i am creating a po based on cost centre and project a mail should be fired to the respective user who has created that po.

I am trying to solve this issue using the user exit,if some body having the idea how to solve this prob using userexit and the code related to that pls post that,or if there is any other procedure other than the userexit than pls send me the code.

There is a possibility to solve this issue using BADI ,but i dont have any idea about this so pls help me if there is any other procedure.

Thanks a lot

mrutyun^