Simple PHPBB3 Authentication Bridge

<?php 
 
/////////////////////////////////////////////////
// BEGIN SESSION AND AUTHENTICATION MANAGEMENT //
///////////////////////////////////////////////// 
 
define('IN_PHPBB', true);
$phpbb_root_path = './Forum/';
$phpEx = substr(strrchr(__FILE__, '.'), 1);
include($phpbb_root_path . 'common.' . $phpEx);
// Start session management
$user->session_begin();
$auth->acl($user->data);
$user->setup(); 
 
///////////////////////////////////////////////
// END SESSION AND AUTHENTICATION MANAGEMENT //
/////////////////////////////////////////////// 
 
// is user logged in?
if($user->data['is_registered']){ 
 
    echo 'Weclome ';
    print $user->data['username'];
    echo '!<br />
    <a title="Click here to logout!" href="'.append_sid("{$phpbb_root_path}ucp.$phpEx", 'mode=logout', true, $user->session_id). '">Log out</a>';
}
else{ 
 
    echo '
    <form method="post" action="Forum/ucp.php?mode=login">
<label for="username">Username: </label> <input type="text" name="username" id="username" size="40" /><br /><br />
<label for="password">Password: </label><input type="password" name="password" id="password" size="40" /><br /><br />
<label for="autologin">Remember Me?: </label><input type="checkbox" name="autologin" id="autologin"  /><br /><br />
<input type="submit" value="Log In" name="login" />
<input type="hidden" name="redirect" value="../login.php" />
</form> 
 
<a title="Register" href="forum/ucp.php?mode=register">Register</a> 
 
    ';
}