public void fillAndRemoveFromUserLists(JList uList, JList userOnTaskLlist, ArrayList<User> userOnTask) throws SQLException, IOException {

        DefaultListModel model = (DefaultListModel) uList.getModel();
        DefaultListModel modelOnTask = (DefaultListModel) userOnTaskLlist.getModel();

        model.clear();
        for (int i = 0; i < userList.size(); i++) {
            model.addElement(userList.get(i));

        }
        modelOnTask.clear();

        for (int i = 0; i < userOnTask.size(); i++) {
            modelOnTask.addElement(userOnTask.get(i));
            for (int j = 0; j < userList.size(); j++) {
                if (modelOnTask.get(i).toString().equals(userList.get(j).getUserName().toString())) {
                    model.removeElement(userList.get(j));
                }
            }
        }
    }