function css_browser_selector(u) {
    var ua = u.toLowerCase(),
    is = function (t) {
        return ua.indexOf(t) > -1;
    },
    g = 'gecko',
    w = 'webkit',
    s = 'safari',
    h = document.getElementsByTagName('html')[0],
    b = [(!(/opera|webtv/i.test(ua)) && /msie\s(\d)/.test(ua)) ? ('ie ie' + RegExp.$1) : is('firefox/2') ? g + ' ff2': is('firefox/3') ? g + ' ff3': is('gecko/') ? g: /opera(\s|\/)(\d+)/.test(ua) ? 'opera opera' + RegExp.$2: is('konqueror') ? 'konqueror': is('chrome') ? w + ' chrome': is('applewebkit/') ? w + ' ' + s + (/version\/(\d+)/.test(ua) ? ' ' + s + RegExp.$1: '') : is('mozilla/') ? g: '', is('j2me') ? 'mobile': is('iphone') ? 'iphone': is('ipod') ? 'ipod': is('mac') ? 'mac': is('darwin') ? 'mac': is('webtv') ? 'webtv': is('win') ? 'win': is('freebsd') ? 'freebsd': (is('x11') || is('linux')) ? 'linux': '', 'js'];
    c = b.join(' ');
    h.className += ' ' + c;
    return c;
};
css_browser_selector(navigator.userAgent);