如何拦截方法调用？

i'm creating a user panel, and i want to allow methods depending on the user state, if is logged on or isn't, wich method is called by the url, for example:

funciton home () {...}
function create_account () {...}

the create_account method is only available if the user's off, and the home when he is on, what i'm doing individually is something like this:

function home () {
if(!$userLogged)
die('Ei, little satan, you can't enter here!');
}

How can i intercept all methods that have been called and make some rules?

    function __interceptAll($method) {
    $userOff = array('create_account'...);
    $userOn = array('home','change'...);

    if(in_array)....
}