http post connection hatası

HttpClient hc = new DefaultHttpClient();

    String message;

    HttpPost p = new HttpPost("http://localhost:5296/api/Mail/Send");

    JSONObject json = new JSONObject();

    try {

        json.put("Ad", ad.getText().toString());

        json.put("Telefon", telefon.getText().toString());

        json.put("Tarih", tarih.getText().toString());

        json.put("Urun", urun.getText().toString());

        json.put("Adet", adet.getText().toString());

        json.put("Mesaj", mesaj.getText().toString());

    } catch (Exception ex) {

    }

    try {

        message = json.toString();

        p.setEntity(new StringEntity(message, "UTF8"));

        p.setHeader("Content-type", "application/json");

        HttpResponse resp = hc.execute(p);

        Log.d("Status line", "" + resp.getStatusLine().getStatusCode());

    } catch (Exception e) {

        e.printStackTrace();

    }

}

bu  kodda connection hatası nerede va?