event对象

获得event对象兼容性写法 
event || (event = window.event);

获得target兼容型写法 

event.target||event.srcElement

阻止浏览器默认行为兼容性写法 
event.preventDefault ? event.preventDefault() : (event.returnValue = false);

阻止冒泡写法 
event.stopPropagation ? event.stopPropagation() : (event.cancelBubble = true);