Extending Element class in a dom tree?

The DOM implementation i PHP5 allows classes to be extended. Extending the Document class is no problem, but how can I extend the Element class and use it in a DOM tree? DOMDocument::createElement returns a DOMElement object which you cannot extend. Could this be a solution? class MyElement extends DomElement {

    function __construct($a_stTagName) {
        //has to be called!
        parent::__construct($a_stTagName);
    }

    function myFunction() {

// do something

    }

} $oDom = new DomDocument(); $oMyElement = new MyElement('mytag'); $oMyElement = $oDom->importNode($oMyElement, true); $oMyElement = $oDom->appendChild($oMyElement); Regards /Erik