public function loginUser() {


        $mysqli = MysqliConnect::dbConnect();

        if (isset($_POST['send'])) {
            $parameters = array();
            $results = array();
            $username = $mysqli->real_escape_string(trim($_POST['username']));
            $userpassword = sha1(trim($_POST['userpassword']));
            $query = "SELECT userid,
            firstname,
            lastname,
            admin,
            userpassword
            FROM users
            WHERE username = '$username'
            AND
            userpassword = '$userpassword' LIMIT 0 , 1";


            $stmt = $mysqli->prepare($query);
            $stmt->execute();

            $results = dynamicHandler::dynamicBindResults($stmt);

            foreach ($results as $row) :
                $_SESSION['user'] = $row['userid'];
                $_SESSION['firstname'] = $row['firstname'];
                $_SESSION['lastname'] = $row['lastname'];
                $_SESSION['admin'] = $row['admin'];
            endforeach;

            if (empty($results)) {
                global $error;
                $error->getMessage(1);
            } else {
                header("Location: index.php");
                exit;
        }
        }
        return;
    }