Problem with sessions!

I'm having a annoying problem with sessions. I've been making a knowledge test basically using two files. file1.php that gets username, starts session, gets number of files from a database etc. file2.php that show the questions from the database and then returns the answer to file1.php using a ordinary A HREF. Everything works fine until it's supposed to close the session (with session_destroy();) the session gets destroy (i don't get a error message anyway) and all the outputs are fine. But if i start the program again from the same browser instance it returns the old data (like username). So the only thing i know to destroy the session is to close the browser! I start the session with session_start(); and then i register a bunch of variables the first time the page is accessed.. and when all output is done i do session_unset(); session_destroy(); exit; And close the window (but there's another window behind it) Please help.. i've tried basically everything but i can't seem to solve it!!!