private function add()
 {
     if (isset($_POST['send'])) {
         if (is_uploaded_file($_FILES['pic']['tmp_name'])) {
             $upload = new UploadFile("pic", "public/uploads/download");
             $upload->setAllowType(array('zip'));
             if ($upload->upload("pic")) {
                 $this->model->name = $upload->getNewName();
             }
         } else {
             $this->model->url = $_POST["url"];
         }
         $this->model->description = $_POST["description"];
         $this->model->tid = $_POST["tid"];
         $this->model->title = $_POST["title"];
         if ($this->model->addDownload()) {
             Tools::Redirect("添加上传内容成功", "?a=download&action=show");
         } else {
             Tools::Redirect("添加上传内容失败", $_SERVER['HTTP_REFERER'], 2);
         }
     }
     $this->topic();
     $this->smarty->assign("add", true);
 }