浮动的图层总是被其它图层覆盖（加急）

<script language="JavaScript">
    var delta=0.15
    var collection;
    function floaters() {
        this.items    = [];
        this.addItem    = function(id,x,y,content)
                  {
                    document.write('<DIV id='+id+' style="Z-INDEX: 10; POSITION: absolute;  width:80px; height:60px;left:'+(typeof(x)=='string'?eval(x):x)+';top:'+(typeof(y)=='string'?eval(y):y)+'">'+content+'</DIV>');
                    
                    var newItem                = {};
                    newItem.object            = document.getElementById(id);
                    newItem.x                = x;
                    newItem.y                = y; 
                    this.items[this.items.length]        = newItem;
                  }
        this.play    = function()
                  {
                    collection                = this.items
                    setInterval('play()',10);
                  }
        }
        function play()
        {
            if(screen.width<=800)
            {
                for(var i=0;i<collection.length;i++)
                {
                    collection[i].object.style.display    = 'none';
                }
                return;
            }
            for(var i=0;i<collection.length;i++)
            {
                var followObj        = collection[i].object;
                var followObj_x        = (typeof(collection[i].x)=='string'?eval(collection[i].x):collection[i].x);
                var followObj_y        = (typeof(collection[i].y)=='string'?eval(collection[i].y):collection[i].y); 
                if(followObj.offsetLeft!=(document.body.scrollLeft+followObj_x)) {
                    var dx=(document.body.scrollLeft+followObj_x-followObj.offsetLeft)*delta;
                    dx=(dx>0?1:-1)*Math.ceil(Math.abs(dx));
                    followObj.style.left=followObj.offsetLeft+dx;
                    } 
                if(followObj.offsetTop!=(document.body.scrollTop+followObj_y)) {
                    var dy=(document.body.scrollTop+followObj_y-followObj.offsetTop)*delta;
                    dy=(dy>0?1:-1)*Math.ceil(Math.abs(dy));
                    followObj.style.top=followObj.offsetTop+dy;
                    }
                followObj.style.display    = '';
            }
        }    
        
    var theFloaters = new floaters();
theFloaters.addItem('followDiv1','document.body.clientWidth-108',80,'<br><div align=left><a href=# onclick=document.getElementById("followDiv1").style.visibility="hidden";document.getElementById("followDiv2").style.visibility="hidden">关闭</a></div><object classid=clsid:D27CDB6E-AE6D-11cf-96B8-444553540000 codebase=http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0 width=105 height=300>  <param name=movie value=lefeflash.swf>  <param name=quality value=high>  <embed src=lefeflash.swf quality=high pluginspage=http://www.macromedia.com/go/getflashplayer type=application/x-shockwave-flash width=105 height=300></embed></object>');
   theFloaters.addItem('followDiv2',6,80,'<br><div align=right><a href=# onclick=document.getElementById("followDiv1").style.visibility="hidden";document.getElementById("followDiv2").style.visibility="hidden">关闭</a></div><object classid=clsid:D27CDB6E-AE6D-11cf-96B8-444553540000 codebase=http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0 width=105 height=300>  <param name=movie value=lefeflash.swf>  <param name=quality value=high>  <embed src=lefeflash.swf quality=high pluginspage=http://www.macromedia.com/go/getflashplayer type=application/x-shockwave-flash width=105 height=300></embed></object>'); 
    theFloaters.play();    
</script>参考这个可能好点