protected JSONObject doInBackground(String... params) {
    try {

        //Url
        api = ServiceUrl.getBaseUrl() + ServiceUrl.getLoginUrl();
        //build JsonObject
        jsonParams = new JSONObject();
        String userName = this.muserName; // params[0] is username
        String password = this.mpassword; // params[1] is password
        jsonParams.put("user_name", userName);
        jsonParams.put("password", password);

        ServerRequest request = new ServerRequest(api, jsonParams);
        return request.sendRequest();

    } catch (UnknownHostException e) {
        progressDialog.dismiss();
        activity.showAlert("Please check internet connection.");
        return Excpetion2JSON.getJSON(e); // returns exception here
    }catch (JSONException je) {
        progressDialog.dismiss();
        activity.showAlert("Please check internet connection.");
        return Excpetion2JSON.getJSON(je); // returns exception here
    }

}