code: function isActiveElement(elmn) {
  				var result = false;
  				try {
  					result = elmn === document.activeElement;
  				} catch (error) {}
  				return result;
  			}
docs: IE9: getting activeElement in an iframe raises error http://tjvantoll.com/2013/08/30/bugs-with-document-activeelement-in-internet-explorer/