DIV+CSS弹窗

<style>
.AsaiDivBG{display:none;position:absolute;top:0%;left:0%;width:100%;height:100%;background-color:white;z-index:1001;-moz-opacity:0.8;opacity:.80;filter:alpha(opacity=80);}
.AsaiDivShow{display:none;position:absolute;left:8px;top:8px;width:580px;height:320px;padding:8px;border:8px solid orange;background-color:white;z-index:1008;overflow:auto;}
</style>
<a href="javascript:void(0)" onclick = "document.getElementById('asaimsg').style.display='block';document.getElementById('asaimsgbg').style.display='block'">点击预览效果</a>

<div id="asaimsg" class="AsaiDivShow">

<P align=center>
<a href="javascript:void(0)" onclick = "document.getElementById('asaimsg').style.display='none';document.getElementById('asaimsgbg').style.display='none'"><FONT color=#ff0000>关闭本窗口</FONT></a></P>

</div>

<div id="asaimsgbg" class="AsaiDivBG"></div>