Event.observe(window, 'load', function() {
    var maintenancePopup = new lightwindow();
    $$('.payment-maintanence').each(function(el) {
        Event.observe(el, 'click', function(e) {
            e.stop();
            maintenancePopup.activateWindow({
                href: BASE_URL + "payment-maintenance",
                type: 'page',
                title: '',
                width: 500,
                height: 300
            });
        });
    });
});