Defer Loading of External CSS Until Page Loaded

defer.ext.css.js

var cb = function() {
    var l = document.createElement('link'); l.rel = 'stylesheet';
    l.href = '//ajax.googleapis.com/ajax/libs/jqueryui/1.11.1/themes/smoothness/jquery-ui.css';
    var h = document.getElementsByTagName('head')[0]; h.insertBefore(l, h.lastChild);
};
var raf = requestAnimationFrame || mozRequestAnimationFrame ||
    webkitRequestAnimationFrame || msRequestAnimationFrame;
if (raf) raf(cb);
else if (window.addEventListener) window.addEventListener('load', cb);
else if (window.attachEvent) window.attachEvent("onload", cb);
else window.onload = cb;

// from http://codesr.thewebflash.com/2014/08/defer-loading-external-css-until-page.html