code: function loadStylesheetsFallingBack(stylesheets) {
      var n = stylesheets.length;
      function load(i) {
        if (i === n) { return; }
        var link = doc.createElement('link');
        link.rel = 'stylesheet';
        link.type = 'text/css';
        if (i + 1 < n) {
          // http://pieisgood.org/test/script-link-events/ indicates that many
          // versions of IE do not support onerror on <link>s, though
          // http://msdn.microsoft.com/en-us/library/ie/ms535848(v=vs.85).aspx
          // indicates that recent IEs do support error.
          link.error = link.onerror = function () { load(i + 1); };
        }
        link.href = stylesheets[i];
        head.appendChild(link);
      }
      load(0);
    }
docs: Given a list of URLs to stylesheets, loads the first that loads without triggering an error event.