Detect IE and add class to the html element

gistfile1.js

// Including IE detection by James Padolsey: https://gist.github.com/527683
(function (html) {
    var ie = (function () {
            var undef,
                v = 3,
                div = document.createElement('div'),
                all = div.getElementsByTagName('i');
            while (div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->', all[0]);
            return (v > 4)? v: undef;
        }());
    if (ie) {
        html.className += ' ie' + ie;
    }
})(document.documentElement);