Problemer med login script.

Hej Eksperter. Jeg har følgende login script, som jeg efter lidt omrokering, har fået fucked helt op. Hvis der findes nogle derude som kan hjælpe mig lidt ville det være kanon.
Den melder fejlmedelelse hver gang jeg forsøger at logge ind.
Er virkelig kørt død i den. Håber at nogle gider hjælpe.

Login.php--------
<?php
print_r($_POST);
require_once('login_funcs.php');


if ($LOGGED_IN = user_isloggedin()) {
    user_logout();
    $_COOKIE['username'] = '';
    unset($LOGGED_IN);
}

// Return-koder
define('ACCT_OK', 0 );
define('ACCT_NOTCONFIRMED', 1);
define('ACCT_NOTNOTFOUNDORPWINCORRECT', 2);

// Input variablerne
if( isset($_POST['username']) )
  $username = $_POST['username'];
else
  $username = '';

if( isset($_POST['password']) )
  $password = $_POST['password'];
else
  $password = '';

// Besked til brugeren
$feedback_str = '';

if( !empty($username) && !empty($password) ) {
  $res = user_login($username,$password);
 


  switch($res) {
      case ACCT_OK:
        header("location; index.php");
        exit;
        break;

      case ACCT_NOTCONFIRMED:
        $feedback_str = 'ERROR--You may not have confirmed your account yet';
        break;

      case ACCT_NOTNOTFOUNDORPWINCORRECT:
        $feedback_str = 'ERROR--User not found or password incorrect';
        break;
  }
}
else {
  if( count($_POST) != 0 )  // Brugeren har trykket submit (eller return)
      $feedback_str = 'ERROR--Please supply username and password';
}

// vis html-form som før.

$php_self = $_SERVER['PHP_SELF'];

$login_form = <<< EOLOGINFORM
<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 ALIGN=Center Width=621>
<tr>
<td rowspan=2></td></tr>
<tr>
<td>
$feedback_str
<p class="bold">LOGIN</P>
<form action="$php_self" method="post">
<p class="bold">Username<BR>
<input type="text" name="username" value="" size="15" maxlength="20"></p>
<p class="bold">password<br>
<input type="password" name="password" value="" size="15" maxlength="20"></p>
<p><input type="submit" name="submit" value="login"></p>
</form>
</td>
</tr>
</table>
EOLOGINFORM;
echo $login_form;

?>
---------------------------------------------------------

Login_funcs.php----

<?php

include_once('db_vars.inc');

$supersecret_hash_padding = 'A string that is used to pad out short strings for md5 encryption';

$LOGGED_IN = false;
unset($LOGGED_IN);

function user_isloggedin() {
    global $supersecret_hash_padding, $LOGGED_IN;

    if (isSet($LOGGED_IN)) {
        return $LOGGED_IN;
    }

    if (isset($_COOKIE['username']) && isset($_COOKIE['id_hash'])) {
        $hash = md5($_COOKIE['username'].$supersecret_hash_padding);
        if ($hash == $_COOKIE['id_hash']) {
            return true;
        }
        else {
            return false;
        }
    }
    else {
        return false;
    }
}

/*function user_login() {
    if (!$_POST['username'] || !$_POST['password']) {
        $feedback = 'ERROR--Missing username or password';
        return $feedback;
    }
    else {
        $username = strtolower($_POST['username']);
        $password = strtolower($_POST['password']);
        $crypt_pwd = md5($password);
        $query = "SELECT username, is_confirmed
        FROM login
        WHERE username = '$username'
        AND password='$crypt_pwd'";
        $result = mysql_query($query);
        if (!$result || mysql_num_rows($result) < 1){
            $feedback = 'ERROR--User not found or password incorrect';
            return feedback;
        }
        else {
            if (mysql_result($result, 0, 'is_confirmed') == '1') {
            user_set_tokens($username);
            return 1;
            }
            else {
                $feedback = 'ERROR--You may not have confirmed your account yet';
                return $feedback;
            }
        }
    }
}*/

function user_login($username,$password) {
  $username = strtolower($username);
  $password = strtolower($password);
  $crypt_pwd = md5($password);
  $query = "SELECT username, is_confirmed
    FROM login
      WHERE username = '$username'
      AND password='$crypt_pwd'";
  $result = mysql_query($query);

  if (!$result || mysql_num_rows($result) < 1)
      return ACCT_NOTNOTFOUNDORPWINCORRECT;

  if (mysql_result($result, 0, 'is_confirmed') == '1') {
      user_set_tokens($username);
      return ACCT_OK;
  }
  else {
      return ACCT_NOTNOTFOUNDORPWINCORRECT;
    }
}

function user_logout() {
    setcookie('username', '', (time()+2592000), '/', '', 0);
    setcookie('id_hash', '', (time()+2592000), '/', '', 0);
}

function user_set_tokens($username_in) {
    global $supersecret_hash_padding;
    if (!$username_in) {
        $feedback = 'ERROR--No username';
        return false;
    }
    $username = strtolower(username_in);
    $id_hash = md5($username.$supersecret_hash_padding);

    setcookie('username', $username, (time()+2592000), '/', '', 0);
    setcookie('id_hash', $id_hash, (time()+2592000), '/', '', 0);

}

?>
---------------------------------------------