public function addHead()
 {
     if (($head = I('post.head')) != '' && !empty($_FILES['head_image']['name'])) {
         $IS = new ImageService();
         $info = $IS->uploadHead($head, $_FILES['head_image']);
         if ($info !== true) {
             $this->error($info, U('Image/addHead'), 2);
         }
         redirect(U('Image/head'));
     }
     $this->display('addHead');
 }