Originally Posted by capypara
if those scripts are just a small part of yr complete code (that relates to this problem) then the problem may lie somewhere else. otherwise as what other posters have said, you are not passing any value into your Session[username] at all.
The problem is definitely what's above. You can see that there is no assignment to the session variables, and no session_start() at the top of his page.
But, it's logical to assume that there could be errors in other files as well - just nothing that will relate to this immediate problem.