模拟注册post问题（GetRequestStream后必须要GetResponse）

//模拟注册
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://login.sina.com.cn/signup/signup1.php");
            request.CookieContainer = cookies;
            request.Method       = "POST";
            request.Accept       = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
            request.Referer      = "http://login.sina.com.cn/signup/signup.php";
            request.ContentType  = "application/x-www-form-urlencoded";
            request.ContentLength = postData.Length;
            Stream myRequestStream = request.GetRequestStream();
            using (StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312")))
            {
                myStreamWriter.Write(postData);
            }
            myRequestStream.Close();
            WebResponse response = request.GetResponse();//这个不能省略，否则发生意外错误
            response.Close();
            //模拟注册 end