hello

i wrote a program that post some data to a server. the server response only if the correct browser identification was transmitted - i think so is this realy possible that a server dont send information if no browser id available or the wrong one?
however please tell me how can i set the browser id? i use the webclient class:
WebClient wc = new WebClient();
wc.Headers.Add("Content-Type","application/x-www-form-urlencoded");

and so on...