function show_hide(el) {
        if (/(^| )hidden-js( |$)/.test(el.className)) {
            el.className = el.className.replace(/(^| )hidden-js( |$)/, '$2');
        } else {
            el.className += ' hidden-js';
        }
        return true;
    }
    document.write('<style>.hidden-js { display: none; }<' + '/style>');