final public function parent()
    {
        $parent = NULL;

        if(!!isset($this->dom_element->parentNode))
        {
            if($this->dom_element->parentNode->nodeType == 1)
            {
                $parent = new PHPHtmlDomElement($this->dom_element->parentNode);
            }
            else
            {
                $parent = $this->dom_element->parentNode;
            }
        }
        return $parent;
    }