将html form 内容写到后盾

将html form 内容写到后台

  <form action="https://www.paypal.com/cgi-bin/webscr" method="post">
  <input type="hidden" name="cmd" value="_xclick" >
  <input type="hidden" name="business" value="test@test.com" >
  <input type="hidden" name="item_name" value="testtest" >
  <input type="hidden" name="currency_code" value="USD" >
  <input type="hidden" name="amount" value="100.00" >
    <input type="image" src="https://www.paypal.com/en_US/i/btn/x-click-but23.gif" border="0"
        name="submit" alt="Make payments with PayPal - it's fast, free and secure!">
    </form>

 protected void Button1_Click(object sender, EventArgs e)
    {
        string postData = "";
        postData += "cmd=_xclick";
        postData += "&business=test@test.com";
        postData += "&item_name=testtest";
        postData += "&currency_code=USD";
        postData += "&amount=100.00";
        byte[] data = Encoding.Default.GetBytes(postData);
        HttpWebRequest ppRequest = (HttpWebRequest)
         WebRequest.Create("https://www.paypal.com/cgi-bin/webscr"); ;
        ppRequest.Method = "POST";
        ppRequest.ContentType = "application/x-www-form-urlencoded";
        ppRequest.ContentLength = data.Length;

        Stream ppStream = ppRequest.GetRequestStream();
        ppStream.Write(data, 0, data.Length);
        ppStream.Close();

        HttpWebResponse ppResponse = (HttpWebResponse)ppRequest.GetResponse();
        StreamReader sr = new StreamReader(ppResponse.GetResponseStream());
        string strResult = sr.ReadToEnd();
        sr.Close();
 
        Response.Clear();
        Response.Write(strResult);
        Response.End();

    }

这样提交过去不对。
------解决方案--------------------------------------------------------
我用你的代码  请求时请求过去了  
但是显示了
Sorry — your last action could not be completed

不知道是不是LZ的参数有误还是怎么的
------解决方案--------------------------------------------------------
帮顶！