// requestAnim shim layer by Paul Irish
window.requestAnimFrame = (function() {
  return  window.requestAnimationFrame       ||
          window.webkitRequestAnimationFrame ||
          window.mozRequestAnimationFrame    ||
          window.oRequestAnimationFrame      ||
          window.msRequestAnimationFrame     ||
          function(/* function */ callback, /* DOMElement */ element) {
            window.setTimeout(callback, 1000 / 60);
          };
})();
