public function indexAction()
    {
        if ($this->getRequest()->isAjax()) {
            try {
                $this->loadLayout(null, false, false);
                $this->getLayout()->getUpdate()->setCacheId(null);
                $this->getLayout()->getUpdate()->addHandle(strtolower($this->getFullActionName()) . '_AJAX');
            } catch (Exception $e) {
                Mage::logException($e);
                $this->getResponse()->setHeader('Content-Type', 'application/json');
                $this->getResponse()->setBody(Zend_Json::encode(['error' => true, 'message' => $e->getMessage()]));
            }
        }

        $this->loadLayout();
        $this->renderLayout();
    }