/**
  * user login action
  */
 public function indexAction()
 {
     // clear layout
     $this->clearLayout();
     if ($this->request->isPost()) {
         // submit login
         $username = $this->request->getPost('username', 'trim');
         $password = $this->request->getPost('password', 'trim');
         $isremember = $this->request->getPost('isremember', 'trim');
         $user = Users::getUserByName($username);
         if ($user) {
             // account info ok
             if ($user->password == md5(md5($password) . $user->salt)) {
                 // password is right
                 if ($user->status == 1) {
                     // allow login
                     $this->session->set('adminAuth', serialize($user));
                     return $this->response->redirect('/Admin');
                 } else {
                     $this->assign('errorMessage', '您的账户被锁定');
                 }
             } else {
                 // password fail
                 $this->assign('errorMessage', '您的密码错误');
             }
         } else {
             // not fond this account
             $this->assign('errorMessage', '您的账户未找到');
         }
     }
 }