If it's HTTP validation, send a request to the proxy to see if there is a response! HttpWebRequest objHttpRequest; HttpWebResponse objResponse; WebProxy objProxy; objHttpRequest=(HttpWebRequest)WebRequest.Create(m_strUrl); objHttpRequest.Timeout=3000; objHttpRequest.AllowAutoRedirect=true; objHttpRequest.ContentType="application/x-www-form-Urlencoded"; objProxy=new WebProxy(ProxyName,PortID); objProxy.BypassProxyOnLocal=true; objProxy.Credentials=new NetworkCredential(UserID,Pwd,Domain);...