一个点击可显示再点击隐藏层的代码，并可随浏览器滚动条拉伸而滚动，可广泛适用于广告、在线客服、快捷留言发布等功能的精短代码。

<div style='width:100px;height:100px;position:absolute;left:-200px;top:80px;background:#FFCC00;border:1px solid #999;'>点击可隐藏</div>
<div style='position:absolute;left:2px;top:80px;'><img src=alt='点击打开' /></div>
<script type='text/Ｊavascript'>
<!--
        var i=0, str='';while(i++<100){str+='<br>'}
        document.write(str);

        var c=0;
        var div = document.getElementsByTagName('div')[0];
        var img = document.getElementsByTagName('div')[1];

        div.Ｏnclick = function(){
                img.style.left = '2px';
                div.style.left = '-200px';
        }

        img.Ｏnclick = function(){
                div.style.left = '2px';
                img.style.left = '-200px';
        }

        var y = parseInt(div.style.top);
        var my = parseInt(img.style.top);

        window.onscroll = function(){
                clearInterval(c);
                c = setInterval(function(){
                        var cy = parseInt(div.style.top);
                        var mcy = parseInt(img.style.top);
                        var dy = document.body.scrollTop || document.documentElement.scrollTop;
                        div.style.top = (cy + (dy -(cy-y))*0.1) + 'px';
                        img.style.top = (mcy + (dy -(mcy-my))*0.1) + 'px';
                },10);
        }
//-->
</script>

IE6.0和Fire火狐浏览器中测试通过，其他未测试。Ｊ和Ｏ改成小写的字母j和o