public function indexAction()
{
$this->view->Title = "Quản lý nhóm sản phẩm";
$this->view->headTitle($this->view->Title);
$page = $this->getRequest()->getParam('page');
$condition = array();
list($this->view->Pager, $this->view->Productgroup) = ProductGroup::getAll($condition, $page);
}