(function(){
    var base_url;
    var f = 'mac.js';
    var s = document.getElementsByTagName('script');

    for (var i = 0, n = s.length; i < n; i ++) {
        if (s[i].src.match(f)) {
            var span_element = document.createElement('span');
            span_element.innerHTML = '<a href="' + s[i].src + '" />';
            base_url = span_element.firstChild.href.replace('/js/' + f, '');
            break;
        }
    }

    if (navigator.appVersion.indexOf("Mac") != -1) {
        document.write('<link rel="stylesheet" href="' + base_url + '/css/mac.css" type="text/css" />');
    }
})();