private static bool UrlIsExist(string url)

{

    System.Uri u = null;

    try

    {

        u = new Uri(url);

    }

    catch { return false; }

    bool isExist = false;

    System.Net.HttpWebRequest r = System.Net.HttpWebRequest.Create(u) as System.Net.HttpWebRequest;

    r.Method = "HEAD";

    try

    {

        System.Net.HttpWebResponse s = r.GetResponse() as System.Net.HttpWebResponse;

        if (s.StatusCode == System.Net.HttpStatusCode.OK)

        {

            isExist = true;

        }

    }

    catch (System.Net.WebException x)

    {

        try

        {

            isExist = ((x.Response as System.Net.HttpWebResponse).StatusCode != System.Net.HttpStatusCode.NotFound);

        }

        catch { isExist = (x.Status == System.Net.WebExceptionStatus.Success); }

    }

    return isExist;

}