CSS生成带提示的菜单

Title

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<!-- [url]http://www.58mb.com/js[/url] -->
<!-- bbs [url]http://www.58mb.com/bbs--[/url]>

<!-- 把下列代码加入到head区内 -->
<style type="text/css">

#coolmenu{
border: 1px solid black;
width: 170px;
background-color: #E6E6E6;
}

#coolmenu a{
font: bold 13px Verdana;
padding: 2px;
padding-left: 4px;
display: block;
width: 100%;
color: black;
text-decoration: none;
border-bottom: 1px solid black;
}

html>body #coolmenu a{
width: auto;
}

#coolmenu a:hover{
background-color: black;
color: white;
}

#tabledescription{
width: 100%;
height: 3em;
padding: 2px;
filter:alpha(opacity=0);
-moz-opacity:0;
}

</style>

<script type="text/javascript">

var baseopacity=0

function showtext(thetext){
if (!document.getElementById)
return
textcontainerobj=document.getElementById("tabledescription")
browserdetect=textcontainerobj.filters? "ie" : typeof textcontainerobj.style.MozOpacity=="string"? "mozilla" : ""
instantset(baseopacity)
document.getElementById("tabledescription").innerHTML=thetext
highlighting=setInterval("gradualfade(textcontainerobj)",50)
}

function hidetext(){
cleartimer()
instantset(baseopacity)
}

function instantset(degree){
if (browserdetect=="mozilla")
textcontainerobj.style.MozOpacity=degree/100
else if (browserdetect=="ie")
textcontainerobj.filters.alpha.opacity=degree
else if (document.getElementById && baseopacity==0)
document.getElementById("tabledescription").innerHTML=""
}

function cleartimer(){
if (window.highlighting) clearInterval(highlighting)
}

function gradualfade(cur2){
if (browserdetect=="mozilla" && cur2.style.MozOpacity<1)
cur2.style.MozOpacity=Math.min(parseFloat(cur2.style.MozOpacity)+0.2, 0.99)
else if (browserdetect=="ie" && cur2.filters.alpha.opacity<100)
cur2.filters.alpha.opacity+=20
else if (window.highlighting)
clearInterval(highlighting)
}

</script>

<!-- 把下列代码加入到body区内 -->
<div id="coolmenu">
<a href="http://www.58mb.com" onMouseover="showtext('JavaScript tutorials and scripts!')" onMouseout="hidetext()">58mb.com</a>
<a href="http://www.58mb.com/js/" onMouseover="showtext('300+ free JavaScripts')" onMouseout="hidetext()">58mb.com</a>
<a href="http://www.58mb.com/jsref/" onMouseover="showtext('Comprehensive JavaScript Reference')" onMouseout="hidetext()">58mb.com</a>
<a href="http://bbs.58mb.com" onMouseover="showtext('Web coding and development forums!')" onMouseout="hidetext()">webjx Forums</a>
<a href="http://www.58mb.com" onMouseover="showtext('Award winning DHTML and JavaScripts')" onMouseout="hidetext()">58mb.com</a>
<div id="tabledescription"></div>
</div>