protected void ButtonLogout_Click(object sender, EventArgs e)
        {
            string authToken = Session["authToken"] as string;

            // Here is the main call to Field API.
            bool result = Glue.Logout(authToken);

            Session["authToken"] = "";

            ButtonLogin.Enabled  = true;
            ButtonLogout.Enabled = false;

            // For our learning,
            // show the request and response in the form.
            ShowRequestResponse();
        }