Find

public function guestAction()
    {
        $parts = explode('_', $_GET['id']);
        $GuestMapper = new Application_Model_GuestMapper();
        $guest = $GuestMapper->find($parts[0]);

        $this->disableView();
        if (isset($parts[1]) && in_array($parts[1], array(1, 2, 3))) {
            $image = 'image' . $parts[1];
            if ($guest && $guest->$image) {
                $content_type = $guest->contentType($parts[1]);
                $path = $guest->imagePath($parts[1]);
            }
            else {
                $content_type = 'image/jpeg';
                $path = Application_Model_Property::noImagePath();
            }
        }
        else {
            $content_type = 'image/jpeg';
            $path = Application_Model_Property::noImagePath();
        }

        $this->getResponse()->setHeader('Content-Type', $content_type);
        readfile($path);
    }