<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title></title>
<style type="text/css">
#l1{
position:absolute;top:100px;left:100px;
width:100px;height:150px;border:1px solid #ccc;
background:#f00;
z-index:1
}
#l2{
position: absolute;top:150px;left:150px;
width:100px;height:150px;border:1px solid #666;
background:#0f0;
z-index:2
}
#l3{
position: absolute;top:200px;left:200px;
width:100px;height:150px;border:1px solid #999;
background:#00f;
z-index:3;
}
</style>
<script type="text/javascript">
var x,y,z,down=false,obj;
function init(){
obj=event.srcElement; //获取焦点对象
obj.setCapture(); //设置鼠标捕捉
z=obj.style.zIndex; //取得原z轴位置
obj.style.zIndex=100; //设定在最上层
x=event.offsetX; //获取鼠标指针相对于触发事件的对象的x位置
y=event.offsetY; //获取鼠标指针相对于触发事件的对象的y位置
down=true; //设置鼠标状态为按下状态
}
function moveIt(){
if(down&&event.srcElement==obj){
with(obj.style){
posLeft=document.body.scrollLeft+event.x-x;
posTop=document.body.scrollTop+event.y-y;
}
}
}
function stopDrag(){
down=false;
obj.style.zIndex=z;
obj.releaseCapture();
}
</script>
</head>
<body>
<div id="l1" onmousedown="init()" onmousemove="moveIt()" onmouseup="stopDrag()">level1</div>
<div id="l2" onmousedown="init()" onmousemove="moveIt()" onmouseup="stopDrag()">level2</div>
<div id="l3" onmousedown="init()" onmousemove="moveIt()" onmouseup="stopDrag()">level3</div>
</body>
</html>