{
    "result": {
        "response": "OK",
        "message": "Authentication was successful.",
        "credencial": {
            "credencial": {
                "name": "hello world",
                "username": "a",
                "email": "a@gmail.com",
                "id": "58"
            }
        }
    }
}

protected void onPostExecute(JSONObject jsonObject) {
            if (jsonObject != null) {
                String jsondata, ddd;

                try {
                    //JSONObject jsonObj = new JSONObject("result");
                    jsondata = jsonObject.getString("result");
                    Toast.makeText(getApplicationContext(), jsondata,
                            Toast.LENGTH_LONG).show();
                    pDialog.dismiss();

                    Intent i = new Intent(LoginActivity.this, MainActivity.class);
                    startActivity(i);
                    finish();

                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    Toast.makeText(getApplicationContext(), "exception",
                            Toast.LENGTH_SHORT).show();
                    pDialog.dismiss();
                }
            }
            //}
        }

protected void onPostExecute(JSONObject jsonObject) {
        if (jsonObject != null) {
            String jsondata, ddd;

            try {
                JSONObject jsonObj = jsonObject.getJsonbject("result");
                JSONObject credencialObj1 = jsonObj.getJsonObject("credencial");
                JSONObject credencialObj2 = credencialObj1.getJsonObject("credencial");

                String name = credencialObj2.getString("name");
                // so on

            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                Toast.makeText(getApplicationContext(), "exception",
                        Toast.LENGTH_SHORT).show();
                pDialog.dismiss();
            }
        }
    }

JSONObject jsonObj = new JSONObject(jsondata);

String message = jsonObj.getString("message");