Add class ieX where X is version to enclosing html tag

ie-add-class.js

(function () {
    "use strict";
    var browserClass = null;
    if (navigator.appName === 'Microsoft Internet Explorer') {
        if (navigator.appVersion.indexOf('MSIE 6', 0) !== -1) {
            browserClass = "ie6";
        } else if (navigator.appVersion.indexOf('MSIE 7', 0) !== -1) {
            browserClass = "ie7";
        } else if (navigator.appVersion.indexOf('MSIE 8', 0) !== -1) {
            browserClass = "ie8";
        } else if (navigator.appVersion.indexOf('MSIE 9', 0) !== -1) {
            browserClass = "ie9";
        }
    }
    if (browserClass) {
        var htmlTag = document.getElementsByTagName("html")[0];
        htmlTag.setAttribute("class", browserClass);
        htmlTag.setAttribute("className", browserClass);
    }
})();