window phone 上POST请求WCF服务的有关问题

window phone 下POST请求WCF服务的问题
我服务端有个WCF服务，这个服务对于在android、IOS，ASP.NET的POSt请求都能正常接收和返回，本人刚接触WP7不久，项目也是使用POST请求WCF，请求部署在本地WCF服务能正常工作，但是请求服务器上的就会出现：“The remote server returned an error:NOtFound”异常，请求代码如下：
HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("http://61.145.163.72:8089/WCFService/Service.svc/Login");
            myRequest.Method = "POST";
            myRequest.ContentType = "application/json";
            myRequest.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), myRequest);
 
private void GetRequestStreamCallback(IAsyncResult asynchronousResult)
        {
            HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
            System.IO.Stream postStream = request.EndGetRequestStream(asynchronousResult);
            string parametersString = "username=admin&password=123456";          
            byte[] byteArray = System.Text.Encoding.UTF8.GetBytes(parametersString);
            postStream.Write(byteArray, 0, parametersString.Length);
            postStream.Close();
            request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request);
        }
 
 
 
 private void GetResponseCallback(IAsyncResult asynchronousResult)
        {
            HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
            HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
            Stream streamResponse = response.GetResponseStream();
            StreamReader streamRead = new StreamReader(streamResponse);
            string responseString = streamRead.ReadToEnd();
            streamResponse.Close();
            streamRead.Close();
       }

运行到  HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
            HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);会抛出“The remote server returned an error:NotFound”异常
      这个问题亟待解决，有哪位前辈和大哥知道告诉小弟，或者帮我提供一下其他WP7下POST请求WCF的方法也行，谢谢了



------解决方案--------------------------------------------------------
postStream.Flush(); 了否
------解决方案--------------------------------------------------------
同问~~