protected void Page_Load(object sender, EventArgs e)
        {
            // Ensure config file is setup
            if (!File.Exists(Server.MapPath(ConfigFile)))
            {
                throw new Exception("Config file not found");
            }

            var serializer = new JavaScriptSerializer();
            string jsonText = System.IO.File.ReadAllText(Server.MapPath(ConfigFile));
            Config = serializer.Deserialize<Dictionary<string, dynamic>>(jsonText);

            if (Config["username"] == "your_api_username")
            {
                throw new Exception("Please configure your username, secret and site_id");
            }

            ObjHd4 = new Hd4(Request, ConfigFile);

            // Models example : Get a list of all models for a specific vendor
            Response.Write("<h1>Nokia Models</h1><p>");
            if (ObjHd4.DeviceModels("Nokia"))
            {
                Response.Write(ObjHd4.GetRawReply());
            }
            else
            {
                Response.Write(ObjHd4.GetError());
            }
            Response.Write("</p>");
        }