cbpoo.
First CHANGE YOUR NAME. Your name is in violation of the
Javaranch Naming Policy. You've been asked to do this before, and many of us feel that if you're not willing to live with the rules of the Javaranch that we don't feel the need to answer your questions.
Second, this is covered quite well in the
InfoCenter (look up section 5 on security) and in the
WAS 4.0 Security Handbook redbook. I would suggest you start looking in both the InfoCenter and in the redbooks site before you post very open-ended questions like this. Remember that Javaranch is run by volunteers and that
you should do your part in making an effort to find an answer to a question before asking someone to help you.
Finally, both links above assume you are using WAS AE (You did not specify which version you were using). If you are using WAS AEs, then the InfoCenter can be found
here.