Uri myuri = new Uri("http://" + System.Web.HttpContext.Current.Request.ServerVariables.Get("HTTP_HOST") + "/" + Request.QueryString["source"].ToString());

            WebRequest myRequest = System.Net.HttpWebRequest.Create(myuri);

            System.Net.IWebProxy proxyObject = new System.Net.WebProxy("http://dummy:80", true);

            myRequest.Credentials = System.Net.CredentialCache.DefaultCredentials;

            myRequest.Proxy = proxyObject;

            Stream result = myRequest.GetResponse().GetResponseStream();

            navDocument.Load(result);