public static string GetClientIP()

        {

            string result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

            if (null == result || result == String.Empty)

            {

                result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

            }

            if (null == result || result == String.Empty)

            {

                result = HttpContext.Current.Request.UserHostAddress;

            }

            return result;

        }