var client = new HttpClient();
   var values = new List<KeyValuePair<string, string>>();
   values.Add(new KeyValuePair<string, string>("task", task));
   values.Add(new KeyValuePair<string, string>("merchant", merchant_id));
   values.Add(new KeyValuePair<string, string>("ref", id));
   // include other fields
   var content = new FormUrlEncodedContent(values);


   **Task<HttpResponseMessage> t =  client.PostAsync("https://voguepay.com/api/", content);**
   t.Wait();
   var response = t.Result;