public function getJavascriptBuilder()
    {
        if (empty($this->jsBuilder)) {
            if (!class_exists('HTML_QuickForm2_JavascriptBuilder')) {
                HTML_QuickForm2_Loader::loadClass('HTML_QuickForm2_JavascriptBuilder');
            }
            $this->jsBuilder = new HTML_QuickForm2_JavascriptBuilder();
        }
        return $this->jsBuilder;
    }