Get:
   public static string GetURI(string URI) {
     System.Net.WebRequest myWebRequest =
System.Net.WebRequest.Create(URI);
     myWebRequest.Proxy = new System.Net.WebProxy(ProxyString, true);  //
true == don't use proxy for local addresses
     System.Net.WebResponse response = myWebRequest.GetResponse();
     System.IO.StreamReader reader = new System.IO.StreamReader
(response.GetResponseStream());
     return reader.ReadToEnd().Trim();
   }

Post is different
 public static string PostURI(string URI, string Parameters) {
   System.Net.WebRequest req = System.Net.WebRequest.Create(URI);
   req.Proxy = new System.Net.WebProxy(ProxyString, true);  // true ==
don't use proxy for local addresses
   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 OutputStream = req.GetRequestStream ();
   OutputStream.Write (bytes, 0, bytes.Length);
   OutputStream.Close ();
   System.Net.WebResponse resp = req.GetResponse();
   if (resp== null) return null;
   System.IO.StreamReader MyStreamReader = new
System.IO.StreamReader(resp.GetResponseStream());
   return MyStreamReader.ReadToEnd().Trim();
}

If you need authentication, you need to add that yourself.

-D