Say, before you login, the page looks normal, a link to login and what not. Then once you logged in, you can see some other stuff. Like instead of a link to login, but a link to log out. And a section thats there when you logged in, but wasn't there when you weren't logged in. Sorry for my newbie-ness
Not I'm really sure how to explain it, hope its clear enough -_-;;
My friend said this, but I don't understand it >.<
Do z-inclusion. Make the login form the first thing to be z-included. Around, the z-inclusion, put the extra links you wanted to put.