this is the code I stole from other people
private XmlDocument FetchXMLfromPostData(String URI, string Parameters)
{
System.Net.WebRequest req = System.Net.WebRequest.Create(URI);
req.ContentType = "application/x-www-form-urlencoded";
req.Method = "POST";
byte[ bytes = System.Text.Encoding.UTF8.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();
if (resp == null) return null;
System.IO.StreamReader sr = new System.IO.StreamReader(resp.GetResponseStream());
Response.Write(sr.ReadToEnd().Trim());
}