credo che quello che cerchi sia negli script forniti da HTML.it
comunque prova a vedere se è questo che ti serve

<HEAD>

<STYLE>

/* This is for Netscape 4.0+ broswsers so that the border will display. If you want to modify the background color this is where you would do it for NS4.0+. To modify the color for IE and NS6 do so in the style tag in the div below
*/

.ttip {border:1px solid black;font-size:12px;layer-background-color:lightyellow;background-color:lightyellow}
</STYLE>

<script>

//Script created by Jim Young (www.requestcode.com)
//Submitted to Website Abstraction (http://wsabstract.com)
//Visit http://wsabstract.com for this script

//Set the tool tip message you want for each link here.
var tip=new Array
tip[0]='Visit Dynamic Drive
for DHTML Scripts!'
tip[1]='Visit Website Abstraction for Great
Scripts, Tutorials and Forums!'
tip[2]='Visit Request Code for FREE JavaScripts!'
tip[3]='Click here for some excellent
Java applets and tutorials'

function showtip(current,e,num)
{
if (document.layers) // Netscape 4.0+
{
theString="<DIV CLASS='ttip'>"+tip[num]+"</DIV>"
document.tooltip.document.write(theString)
document.tooltip.document.close()
document.tooltip.left=e.pageX+14
document.tooltip.top=e.pageY+2
document.tooltip.visibility="show"
}
else
{
if(document.getElementById) // Netscape 6.0+ and Internet Explorer 5.0+
{
elm=document.getElementById("tooltip")
elml=current
elm.innerHTML=tip[num]
elm.style.height=elml.style.height
elm.style.top=parseInt(elml.offsetTop+elml.offsetH eight)
elm.style.left=parseInt(elml.offsetLeft+elml.offse tWidth+10)
elm.style.visibility = "visible"
}
}
}
function hidetip(){
if (document.layers) // Netscape 4.0+
{
document.tooltip.visibility="hidden"
}
else
{
if(document.getElementById) // Netscape 6.0+ and Internet Explorer 5.0+
{
elm.style.visibility="hidden"
}
}
}
</script>

</HEAD>


<!--
inserisci il codice successivo nella sezione <BODY>
-->

<body>
<div id="tooltip" style="position:absolute;visibility:hidden;border: 1px solid black;font-size:12px;layer-background-color:lightyellow;background-color:lightyellow;padding:1px"></div>

Dynamic Drive


Website Abstraction


Request Code


Freewarejava