private boolean alertToDuplicates() {
    for (String screen : mainProjectScreensCBL.getChecked()) {
      if (secondProjectScreensCBL.getChecked().contains(screen)) {
        JOptionPane.showMessageDialog(myCP, "You cannot select two screens with the "
            + "same name. Please uncheck one of the screens and remerge.", "Duplicate error",
            JOptionPane.ERROR_MESSAGE);
        return false;
      }
    }
    for (String asset : mainProjectAssetsCBL.getChecked()) {
      if (secondProjectAssetsCBL.getChecked().contains(asset)) {
        JOptionPane.showMessageDialog(myCP, "You cannot select two assets with the "
            + "same name. Please uncheck one of the assets and remerge.", "Duplicate error",
            JOptionPane.ERROR_MESSAGE);
        return false;
      }
    }
    return true;
  }