$PHP_SELF not working -please help

Hi there, I have created a script that is suppose to get some input from user and display back, and i have the following method <FORM METHOD="POST" ACTION="<? echo $PHP_SELF ?> "> so i have a script that if login fails it will ask the user to register, if(!$username) { session_unregister("userid"); session_uregister("userpassword"); echo "Authorisation Failed." .

      "you must enter a valid credentials.".
      "try again.<BR>\n";

echo "<A HREF=\"$PHP_SELF\">Login</A><BR>"; echo "If you're not a member please regsiter.<BR>\n"; echo "<A HREF=\"$register_script\">Membership</A>"; exit; } else echo "welcome, $username!"; ........ Now for some strange reasons it tries to access my web direcorty that does not contain any file, and i get the 404 page not found error. any help would do, Thanks Caleb _________________________________________________________________ Join the world’s largest e-mail service with MSN Hotmail. http://www.hotmail.com