webrequest post提交不上去

 private void button5_Click(object sender, EventArgs e)
        {
            string a ="address=aaa&kind=住宅房&tel=12332112&userid=asmin&password&admin";
            string dd = "";
            PostPage("http://.../.../send_online/submita.asp",a,"gb2312",out dd);

            
        }
public static string PostPage(string url, string postData, string encodeType, out string err)
        {
            //Stream outstream = null;
            Stream instream = null;
            StreamReader sr = null;
            HttpWebResponse response = null;
            HttpWebRequest request = null;
            string content = null;

            // Encoding encoding = Encoding.UTF8;
            Encoding encoding = Encoding.GetEncoding(encodeType);
            byte[] data = encoding.GetBytes(postData);

            int iConnect = 0;
            while (iConnect < 10) //提交10次，如果不成功则返回null
            {
                // 准备请求... 
                try
                {
                    // 设置参数 
                    request = (HttpWebRequest)WebRequest.Create(url);
                    CookieContainer cookieContainer = new CookieContainer();
                    request.CookieContainer = cookieContainer;
                    request.UserAgent = "5DO8";
                    request.Method = "POST";
                    request.ContentType = "application/x-www-form-urlencoded";
                    request.ContentLength = data.Length;
                    Stream outstream = request.GetRequestStream();
                   
                    outstream.Write(data, 0, data.Length);
                    outstream.Close();

                    //发送请求并获取相应回应数据 
                    response = (HttpWebResponse)request.GetResponse();

                    //直到request.GetResponse()程序才开始向目标网页发送Post请求 
                    instream = response.GetResponseStream();
                    sr = new StreamReader(instream, encoding);

                    //返回结果网页（html）代码 
                    content = sr.ReadToEnd();
                    err = string.Empty;

                    return content;
                }
                catch (Exception ex)
                {
                    err = ex.Message;
                    iConnect++;
                    if (iConnect >= 10)
                        return string.Empty;
                    else continue;
                }
            }

            err = string.Empty;
            if (iConnect >= 10)
                return string.Empty;
            else
                return content;

        }

页面为什么没有提交?!跪求原因! --------------------编程问答-------------------- 调试下,看暴什么异常? --------------------编程问答-------------------- 此法不行可使用XMLHTTPREQUEST对像。。

补充：.NET技术 ,  C#