note 40142 added to function.session-destroy

Hello guys, I'm trying tro make a logout.php but everytime i fail. I get this: Warning: Trying to destroy uninitialized session in /home/virtual/site257/fst/var/www/html/loguit.php on line 7 below you wil see the logout.php : <?php include("connection.php"); $_SESSION = array(); session_destroy(); ?> <html> <head> <title>Je bent succesvol uitgelogd</title> </head> <body> <h1>Basarili bir sekilde çikis yaptiniz.</h1> Basarili bir sekilde çikis yaptiniz. Yeniden giris yapmak için <a href="login.php">tiklayin</a> . </body> </html> pleas help me what can i do? Regards A. Pehlivan ---- Manual Page -- http://www.php.net/manual/en/function.session-destroy.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+40142 Delete -- http://master.php.net/manage/user-notes.php?action=delete+40142&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+40142&report=yes Search -- http://master.php.net/manage/user-notes.php