void Session_Start(object sender, EventArgs e)
        {
            // Code that runs when a new session is started
            ThamSoBUS soLuongTruyCap = new ThamSoBUS();

            soLuongTruyCap.Update();
            // Code that runs when a new session is started
            Application["SoNguoiOnLine"] = (int)Application["SoNguoiOnLine"] + 1;
        }