一个通用事件监听器
./index.html
<script type="text/javascript" src="./monitor.js"></script>
Monitor.addEvent(element,type,function)
/*
element:获取的元素
type:事件类型,没有"on",即类似于click/mousemove
*/
Monitor.removeEvent(element,type,function)
//参数与addEvent一样
Monitor.stopPropagation(event)
Monitor.preventDefault(event)
Monitor.getTarget(event)