protected function get_script_path()
    {
        if( null == $this->script_path )
        {
            $class_name =  substr( get_called_class() , strrpos( get_called_class(), '\\') + 1);
            $this->script_path = $this->get_dir() . '/' . $class_name . '.phtml';
        }
        return $this->script_path;
    }