function isMouseInBox(event,obj){
event=event||window.event;
var point1=new Array(event.clientX+document.body.scrollLeft,event.clientY+document.body.scrollTop);
var point2=getObjPosition(obj);
return( (point1[0]>=point2[0]) && point1[1]>=point2[1] && point1[0]-point2[0]<=obj.offsetWidth && point1[1]-point2[1]<=obj.offsetHeight );
}
function getObjPosition(obj){
var point=new Array(0,0);
while(obj!=document.body){
point[0]+=obj.offsetLeft;
point[1]+=obj.offsetTop;
obj=obj.offsetParent;
}
return point;
}
document.elementFromPoint(x,y); 获取x,y坐标的元素
因为好像IE浏览器中,发生事件后,event是个全局对象,并不需要通过参数传递,另外,event.clientX和 event.x都是返回鼠标坐标的,他们有什么不同么