newb: stop file process

This one should be simple. I am wondering if there is a simple way in which to stop the processing of a file. The current example is a program that checks to see if the user is logged in. In the past I have done something like this: if ($loggedIn != true) { echo "You are not logged in."; } else { echo "Welcome"; } This, however, becomes a substantial problem (or at least annoyance) when the else is pages long. I would prefer to have something like: if ($loggedIn != true) { echo "You're not logged in."; // stop process of file here } // Page content (with no else) The ultimate objective is to have a simple function in the my class include file to verify that the user is always logged in. Thanks in advance.