$error = array();

if(isset($_POST['login'])) {
            $username = ucfirst(strtolower($_POST['username']));
            $pass = $_POST['password'];
            if(empty($username) || empty($pass)) {
                $error[] = 'U heeft een van de velden niet ingevuld!';
            } if(count($error) == 0) {

                $usQ = mysql_query("SELECT
                                        *
                                    FROM
                                        user
                                    WHERE
                                        username = '".in($username)."'
                                    AND
                                        password = '".$pass."'
                ");
                if($usQ)
                {
                    $row = mysql_fetch_object($usQ);
                    if($row->username == $username && $row->password == $pass) {

                        $_SESSION['login'] = array(
                                'session_id'    =>      md5(self::salt(microtime()).microtime()),
                                'user_id'       =>      $row->id,
                                'username'      =>      $row->username,
                                'info'          =>      $_SERVER['HTTP_HOST']
                        );

                    } else { $error[] = 'Een van de gegevens is niet correct.';  }
                } else { return 'Query fout'; }
            } else { return 'fout'; }
        }

if(count($error) > 0) {

            echo "<ul style=\"color:#FF0000;\"> \r\n";
            foreach($error as $erro) {

                echo "\t<li>".$erro."</li> \r\n";

            }
            echo "</ul> \r\n";

        }