private void registering_Click(object sender, EventArgs e)
 {
     if (UserHelper.Inspecter == "")
     {
         new check_login(this).ShowDialog();
     }
     if (UserHelper.Inspecter != "")
     {
         BLL.User user = new BLL.User();
         string   msg  = "";
         if (user.Register(username.Text, password.Text, check_passwrod.Text, name.Text, phone.Text, occupation.Text, out msg))
         {
             MessageBox.Show("注册成功");
         }
         else
         {
             MessageBox.Show(msg);
         }
     }
 }