TcpClient cl = new TcpClient("www.orange.ch", 80);
            //nStream = cl.GetStream();

            //ssl wrapper
            SslStream ssl = new SslStream(cl.GetStream(), false,
                new RemoteCertificateValidationCallback(CertificateValidationCallback));
            try
            {
                ssl.AuthenticateAsClient(serverSN, null, System.Security.Authentication.SslProtocols.Ssl2 |
                System.Security.Authentication.SslProtocols.Ssl3 |
                System.Security.Authentication.SslProtocols.Tls, false);
            }