模拟登录淘宝，进入就提示登录超时，求解

Question

 private void button1_Click(object sender, EventArgs e)
        {
           string getInfo = html.GetResponse("https://login.taobao.com/member/login.jhtml", "", "get", "");           string tb_token = GetTagValue(ref getInfo,"<input name='_tb_token_' type='hidden' value='","'>",false);
            string loginType = GetTagValue(ref getInfo ,"<input type=\"hidden\" name=\"loginType\" value=\"","\" />",false);
            string post = "TPL_username="+this.textBox1.Text+"&TPL_password="+this.textBox2.Text+"&_tb_token_="+tb_token+"&action=Authenticator&event_submit_do_login=anything&TPL_redirect_url=&from=tb&fc=2&style=default&tid=&support=000001&CtrlVersion=1%2C0%2C0%2C7&loginType=3&minititle=&minipara=&pstrong=1&longLogin=-1&llnick=&sign=&need_sign=&isIgnore=&popid=&callback=&not_duplite_str=&need_user_id=&poy=&from_encoding=";
            string userInfo = html.GetResponse("https://login.taobao.com/member/login.jhtml", post, "post", "");
           
                   string url = getData(userInfo, "nekot=", "\";");
           html.redirectUrl = "1";
           string loginOkInfo = html.GetResponse("http://i.taobao.com/my_taobao.htm?nekot=" + url, "", "get", "");
           this.webBrowser1.DocumentText = loginOkInfo;
          
           
            
             
        } public string GetResponse(string url, string postData, string method, string RequestUri)
        {
         
            url.Trim();
            HttpWebRequest request = null;
            try
            {
                request = (HttpWebRequest)WebRequest.Create(url);
            }
            catch
            {
                return "";
            }
            if (request == null)
                return "";
            request.Method = method;
            request.Timeout = 333338;
            request.KeepAlive = true;
            request.AllowAutoRedirect = true;
            request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
            request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; EmbeddedWB 14.52 from: http://www.bsalsa.com/ EmbeddedWB 14.52; .NET CLR 2.0.50727; CIBA)";
            
       //     request.Headers.Add("Accept-Charset", "GB2312,utf-8;q=0.7,*;q=0.7");
            //request.Headers.Add("Accept-Language", "zh-cn,zh;q=0.5");
            //request.Headers.Add("Cookie", "LangKey=cs;");
            request.CookieContainer = myCookieContainer;            if (request.CookieContainer != null)
            {
            string str;
            Uri myuri = new Uri("https://acookie.taobao.com");
            request.Headers.Remove("Cookie");// .RemoveInternal("Cookie");
            string cookieHeader = request.CookieContainer.GetCookieHeader(myuri );//GetCookieHeader(request.Address, out str);
            if (cookieHeader.Length > 0)
            {
                request.Headers["Cookie"] = cookieHeader;
            }
            }
            try
            {
                if (RequestUri != null && RequestUri != "")
                    request.Referer = RequestUri;
                else
                    request.Referer = request.RequestUri.ToString();
            }
            catch
            {
                Console.WriteLine("出错3");
            }            request.ContentType = "application/x-www-form-urlencoded";            HttpWebResponse webresponse = null;
            try
            {
                if (postData.Length > 0)
                {
                    byte[] loginDataBytes = Encoding.Default.GetBytes(postData);
                    request.ContentLength = loginDataBytes.Length;
                    Stream stream = request.GetRequestStream();
                    stream.Write(loginDataBytes, 0, loginDataBytes.Length);
                    stream.Close();
                }
                webresponse = request.GetResponse() as HttpWebResponse;
/////////////////////////////////////////////////////////////////////////////////////////////
                Uri xx = new Uri(url);
                myCookieContainer.SetCookies(xx , webresponse.Headers["Set-Cookie"]);
                MessageBox.Show(webresponse .Headers .ToString ());
                MessageBox.Show(myCookieContainer .Count .ToString ());
               redirectUrl =    webresponse.GetResponseHeader("Location");
             
                   if (webresponse != null)
                {
                    return GetResponseHTML(webresponse);
                }
            }
            catch
            {
                Console.WriteLine("出错");
            }
            finally
            {
                if (webresponse != null)
                {
                    webresponse.Close();
                }
                if (request != null)
                {
                    request.Abort();
                    
                }
            }            return "";
        }