PHP not workingsome one help me plz!

[iGuest 3]

Hi all I am trying to make a login script and its not working! heres the current script I have:

<?phpinclude 'guestbook/includes/connect.php';?><form action="<?php $_SERVER['PHP_SELF']; ?>" method="POST"><table align="center" border="0">  <tr>    <th>Username:</th>	<th><input type="text" name="username"></th>  </tr>  <tr>    <th>Password:</th>	<th><input type="password" name="password"></th>  </tr>  <tr>    <th colspan="2" align="right"><input type="submit" value="Login"></th>  </tr></table></form><?$username = $_POST['username'];$password = $_POST['password'];$sql = @mysql_query("SELECT password, username FROM members");if (!$sql) {    exit("<p>n  <b>Error performing query:</b><br>n" . mysql_error() . "n</p>"); } elseif('username' == $username AND 'password' == $password) {   include 'phpinfo.php'; } ?>

When I tyep my password and username correctly in the login boxes and press submit and if they are correct it'll show the phpinfo.php page but it keeps refreshing to login.php!

Thanx for your help! Aslo I don't want to have a secure login ok. Thanx

[iGuest 3]

did you click submit or press entercoz sumtimes enter does not work...