public async void TestPOST()
 {
     var request = new HttpRequest(new Uri("http://api.jquery.com/"))
     {
         Method = HttpMethod.Post
     };
     var post_stream = request.GetRequestStream();
     request.Headers.ContentType = "application/x-www-form-urlencoded";            
     var bytes = Encoding.UTF8.GetBytes("s=ajax");//search ajax keywords
     post_stream.Write(bytes, 0, bytes.Length);
     post_stream.Close();
     var response = await request.GetResponseAsync().ConfigureAwait(false);
     Assert.AreEqual(200,(int) response.StatusCode);
     using (var sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
     {               
         var index = sr.ReadToEnd().IndexOf("<span>ajax</span>");
         Assert.IsTrue(index > 0);
     }
     response.Close();
 }