code: function getIEEvent() {
      var event = window.event;
      // add event.target
      event.target = event.target || event.srcElement;
  
      event.preventDefault = event.preventDefault || function() {
          event.returnValue = false;
      };
  
      event.stopPropagation = event.stopPropagation || function() {
          event.cancelBubble = true;
      };
  
  	event.key = (event.which + 1 || event.keyCode + 1) - 1 || 0;
  
      return event;
  }
docs: Adapt an native IE event to a new event by monkey patching it