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;
}