/** Called when the Pay Now button is pressed */
  public void onClick(View v) {
    if (v == mBuyButton) {
      if (BillingConstants.DEBUG) {
        Log.d(TAG, "buying: " + mItemName + " sku: " + mSku);
      }

      /** Update the object */
      parkingLocationObj.setAmountPaid(
          mDurationTotalTimeMinutes * FLAT_PARKING_SPOT_RATE_PER_MINUTE);
      parkingLocationObj.setDuration(mDurationTotalTimeMinutes);
      parkingLocationObj.setRate(FLAT_PARKING_SPOT_RATE_PER_MINUTE);
      parkingLocationObj.setQuantity(mTimePeriods);
      parkingLocationObj.setStartTimestampMs(System.currentTimeMillis());
      parkingLocationObj.setEndTimestampMs(
          System.currentTimeMillis() + mDurationTotalTimeMinutes * NUM_MILLIS_IN_A_MINUTE);

      /** Set latitude and longitude in application preferences */
      AppPreferences.getInstance().setLastPaidLocationLatitude(parkingLocationObj.getLatitude());
      AppPreferences.getInstance().setLastPaidLocationLongitude(parkingLocationObj.getLongitude());

      /** Sanity check */
      if (!mBillingService.requestPurchase(mSku, mPayloadContents)) {
        showDialog(DIALOG_BILLING_NOT_SUPPORTED_ID);
      }
    }
  }
  /** Sets up the UI. */
  private void setupWidgets() {
    mBuyButton = (Button) findViewById(R.id.buy_button);
    mBuyButton.setEnabled(false);
    mBuyButton.setOnClickListener(this);

    mSelectLicensePlateSpinner = (Spinner) findViewById(R.id.license_plate_choices);
    ArrayAdapter<String> spinnerArrayAdapter =
        new ArrayAdapter<String>(
            this,
            android.R.layout.simple_spinner_item,
            AppPreferences.getInstance().getLicensePlateList());
    spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    mSelectLicensePlateSpinner.setAdapter(spinnerArrayAdapter);

    // mSelectItemSpinner = (Spinner) findViewById(R.id.item_choices);
    mCatalogAdapter = new CatalogAdapter(this, CATALOG);
    // mSelectItemSpinner.setAdapter(mCatalogAdapter);
    paymentCalculation();
    // mSelectItemSpinner.setOnItemSelectedListener(this);
  }