Find distance between two geo-location in kilometers

public string getDistance(string origin, string destination)
    {
        System.Threading.Thread.Sleep(1000);
        string distance = "";
        string url = "http://maps.googleapis.com/maps/api/directions/xml?origin=" + origin + "&destination=" + destination + "&sensor=false";
        string requesturl = url;

        string content = fileGetContents(requesturl);
        string[] sp = content.Split(' ');


        distance = sp[0].ToString();

        return distance;

    }

    protected string fileGetContents(string fileName)
    {
        string sContents = string.Empty;
        string me = string.Empty;
        try
        {
            if (fileName.ToLower().IndexOf("http:") > -1)
            {
                System.Net.WebClient wc = new System.Net.WebClient();
                byte[] response = wc.DownloadData(fileName);
                sContents = System.Text.Encoding.ASCII.GetString(response);

            }
            else
            {
                System.IO.StreamReader sr = new System.IO.StreamReader(fileName);
                sContents = sr.ReadToEnd();
                sr.Close();
            }
        }
        catch { sContents = "unable to connect to server "; }

        XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.LoadXml(sContents);

        DataSet dsResponse = new DataSet();

        dsResponse.ReadXml(new XmlNodeReader(xmlDoc));
        if (dsResponse.Tables.Count > 0)
        {

            if (dsResponse.Tables.Contains("distance"))
            {
                if (dsResponse.Tables["distance"].Rows.Count > 0)
                {
                    sContents = "";
                    for (int iCount = 0; iCount < dsResponse.Tables["distance"].Rows.Count; iCount++)
                    {
                        sContents = dsResponse.Tables["distance"].Rows[iCount]["text"].ToString();
                    }
                }
            }

        }
        return sContents;
    }


call  getDistance(location1, location2)