How to get IP address details using web service?

protected void Button1_Click(object sender, EventArgs e)
    {
        string xmlResult = null;
        string url;
        url = "http://www.webservicex.net/geoipservice.asmx/GetGeoIP?IPAddress=" + TextBox1.Text + "";
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        StreamReader resStream = new StreamReader(response.GetResponseStream());
        XmlDocument doc = new XmlDocument();
        xmlResult = resStream.ReadToEnd();
        doc.LoadXml(xmlResult);
        if (doc.GetElementsByTagName("ReturnCode").Item(0).InnerText.ToString()== "0")
        {
            Label1.Text = "Invalid IP Address please enter correct address";
            Label2.Text = "";
            Label3.Text = "";
        }
        else
        {
            Label1.Text = "IP Address ofd your System " + doc.GetElementsByTagName("IP").Item(0).InnerText;
            Label2.Text = "Country Name " + doc.GetElementsByTagName("CountryName").Item(0).InnerText;
            Label3.Text = "Country code " + doc.GetElementsByTagName("CountryCode").Item(0).InnerText;
        }
    }