Sessions

[Hypertext]

I'm kind of new with sessions, I'm trying to do a logout.php heres my code.

<?php
session_start()

$dbhost = 'x';
$dbuser = 'x';
$dbpass = 'x';
$dbname = 'x';
mysql_connect($dbhost, $dbuser, $dbpass) or die(mysql_error());

mysql_select_db($dbname);

$user = $_SESSION['user'];

mysql_query("UPDATE `users` SET `online` = '<img src=\"xxx.png\" border=\"0\" />' WHERE `user`='{$user}' ") or die(mysql_error());

 if(session_destroy()) {
 
 echo "<meta http-equiv='refresh' content='0;url=xxx.php'>";
 } 
 else {
 echo "Someting went wrong";
 }
 ?>

Its giving me a blank page, but I was wondering do I need to unregister my session variables?

[MrCraig]

unset($_SESSION["user"]); 

[Hypertext]

nevermind i i got it, i forgot a terminator on session_start(); thanks anyway +rep