Window width and height

var getWindowsWidthAndHeight = function(){
  var w = window,
    d = document,
    e = d.documentElement,
    g = d.getElementsByTagName('body')[0],
    x = w.innerWidth || e.clientWidth || g.clientWidth,
    y = w.innerHeight|| e.clientHeight|| g.clientHeight;
  
  return {width:x,height:y}
}