User _user = new User("user","password","123");

string _parameters = "?username=" + _user.Username
+"&password=" + _user.Password
+"&token=" + _user.Token;

byte[] byteArray = Encoding.ASCII.GetBytes(_parameters);

HttpWebRequest _request = (HttpWebRequest)WebRequest.Create("http://aevitas.in/login.php");
_request.Method = "POST";
_request.ContentType = "application/x-www-form-urlencoded";

Stream _stream = _request.GetRequestStream();

_stream.Write(byteArray, 0, byteArray.Count);

StreamReader _reader = new StreamReader(_stream);
string _serverResponse = _reader.ReadToEnd();

_reader.Close();
_stream.Close();