protected void btnDelete_Click(object sender, EventArgs e)
    {
        int  id  = Convert.ToInt32((sender as LinkButton).CommandArgument);
        bool res = false;

        try
        {
            ChatLieu.ChatLieu_Delete(id);
            res = true;
            Clear();
        }
        catch (SqlException ex)
        {
            Console.WriteLine(ex.Message);
            res = false;
        }

        if (res == true)
        {
            lbSuccess.Text = "Deleted successfully!!";
        }
        else
        {
            lbError.Text = "There's something wrong. We cannot save your work";
        }
    }