protected string Auth()

        {

            String xml;

            String strPhoto = Globals.APP_ROOT_PATH + "common/images/User1_120.png";

            String strPhotoModeImage = Globals.APP_ROOT_PATH + "common/images/User1_40.png";

            String query = "";

             //Check if user filled login and password at the login screen (Chat authorization)

            if (!String.IsNullOrEmpty(Request["user_name"]) && !String.IsNullOrEmpty(Request["password"]))

            {

                query = "SELECT * FROM registered_members WHERE login='" + Request["user_name"].ToString() + "' AND password='" + Request["password"].ToString() + "'";

            }

            // Check session existence with enabled Autologin

            else if (Session["uid"] != null && Session["uid"] != string.Empty)

            {

                query = "SELECT * FROM registered_members WHERE login='" + Session["uid"].ToString() + "'";

            }               

            // Non session/cookie based autologin authorization    

            else if(!String.IsNullOrEmpty(Request["uid"]))

            {

                query = "SELECT * FROM registered_members WHERE login='" + Request["uid"].ToString() + "'";

            }

            else

            {

                xml = "<auth error=\"AUTH_ERROR\" />";

            }

           // Connect to your database to retrieve user's profile info

            if (!string.IsNullOrEmpty(query))

            {

                xml = "<auth error=\"AUTH_ERROR\" />";

                DataTable dt = new DataTable();

                SqlConnection connect = new SqlConnection(ConfigurationManager.ConnectionStrings["LocalSqlServer"].ConnectionString);

                connect.Open();

                SqlDataAdapter ad = new SqlDataAdapter(query, connect);

                ad.Fill(dt);

                connect.Close();

                // Retrieve user's profile info from DataTable and generate xml response

                if (dt.Rows.Count > 0)

                {

                    xml = string.Format("<auth>" +

                  "<userName><![CDATA[{0}]]></userName>" +

                  "<gender>{1}</gender>" +

                  "<level>{2}</level>" +

                  "<photo><![CDATA[{3}]]></photo>" +

                  "<photoModeImage><![CDATA[{4}]]></photoModeImage>" +

                  "</auth>", dt.Rows[0]["username"].ToString(), dt.Rows[0]["gender"].ToString(), dt.Rows[0]["level"].ToString(), strPhoto, strPhotoModeImage);

                }

            }

            else

            {

                xml = "<auth error=\"AUTH_ERROR\" />";

            }      

            return xml;

        }