about http Post

Question

why when i try to send http post , my Project for a few sec send not responding

 

my code

 

 

string ResP = "";

System.Net.WebRequest req = System.Net.WebRequest.Create(URI);

req.ContentType = "application/x-www-form-urlencoded";

req.Method = "POST";

byte[] bytes = System.Text.Encoding.ASCII.GetBytes(Parameters);

req.ContentLength = bytes.Length;

System.IO.Stream os = req.GetRequestStream();

os.Write(bytes, 0, bytes.Length);

os.Close();

System.Net.WebResponse resp = req.GetResponse();

System.IO.StreamReader sr = new System.IO.StreamReader(resp.GetResponseStream());

ResP = sr.ReadToEnd().Trim();