public static string GetClientIP()
        {
            string clientIP = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

            if (string.IsNullOrEmpty(clientIP))
                clientIP = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
            if (string.IsNullOrEmpty(clientIP))
                clientIP = HttpContext.Current.Request.UserHostAddress;
            if (string.IsNullOrEmpty(clientIP))
                clientIP = "0.0.0.0";

            return clientIP;
        }