WebRequest请求一个动态网页

//使用WebRequest请求一个动态网页
HttpWebRequest Http = (HttpWebRequest)WebRequest.Create("http://v3.espacenet.com/results?sf=a&DB=EPODOC&PN=WO03075629+&PGS=10&CY=ep&LG=en&ST=advanced");
WebResponse Resl = Http.GetResponse();
Stream s = Resl.GetResponseStream();
StreamReader sr = new StreamReader(s);
string str = sr.ReadToEnd();
MessageBox.Show(str);这段代码有什么问题吗?为什么得不到结果.哪位高手知道,先谢谢!