parse xml

    public function lowercaseAction()
    {
        $format = $this->getRequest()->getParam('format', 'xml');
        $word = $this->getRequest()->getParam('word', 'Hello');

        switch ($format) {
            case 'json':
                $this->_helper->viewRenderer()->setNoRender(true);
                $this->_helper->json(array ('word' => $word));
                break;
            case 'xml':
            default:
                $this->getResponse()->setHeader('Content-type', 'text/xml');
                $xmlstr = '<word>' . $word . '</word>';
                $xml = new SimpleXMLElement($xmlstr);
                $this->view->xml = $xml->asXML();
                break;
        }
    }