public string GetHtml(string url, string refUrl, string postData, bool isPost, CookieContainer cookieContainer)
        {
            if (string.IsNullOrEmpty(postData))
            {
                return GetHtml(url, cookieContainer);
            }

            byte[] byteRequest = Encoding.Default.GetBytes(postData);

            HttpWebRequest httpWebRequest;
            httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);

            httpWebRequest.CookieContainer = cookieContainer;
            httpWebRequest.ContentType = contentType;
            httpWebRequest.Referer = refUrl;
            httpWebRequest.Accept = accept;
            httpWebRequest.UserAgent = userAgent;
            httpWebRequest.Method = isPost ? "POST" : "GET";
            httpWebRequest.ContentLength = byteRequest.Length;

            Stream stream = httpWebRequest.GetRequestStream();
            stream.Write(byteRequest, 0, byteRequest.Length);
            stream.Close();

            HttpWebResponse httpWebResponse;            
            httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
            Stream responseStream = httpWebResponse.GetResponseStream();
            StreamReader streamReader = new StreamReader(responseStream, encoding);
            string html = streamReader.ReadToEnd();
            streamReader.Close();
            responseStream.Close();

            return html;
        }

            httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();