private void GetAccessToken(string code)
        {
            SageOneOAuth oAuth = new SageOneOAuth();

            oAuth.GetAccessToken(code);

            this.LabelStatus.Text = "You now have access to your Sage One data.  <p>click <a href='Contacts.aspx'>Next</.a> to continue.";

            Session["token"] = oAuth.Token;

        }
        /// <summary>
        /// Authroise the client application to make calls against the API
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void button_authorise_onclick(object sender, EventArgs e)
        {
            SageOneOAuth oAuth = new SageOneOAuth();

            if (oAuth.Token == "")
            {
                Response.Redirect(oAuth.AuthorizationURL);
            }
            else
            {
                Session["token"] = oAuth.Token;
                Response.Redirect("Contacts.aspx");
            }
        }