text: window.requestAnimFrame = (function() {
  	return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
  		function( /* function FrameRequestCallback */ callback, /* DOMElement Element */ element) {
  			return window.setTimeout(callback, 1000/60);
  		};
  })();