Tooltips based on div : Tooltips « GUI Components « JavaScript Tutorial

<html>
<head>
<title>Style Example</title>
<script type="text/javascript">
    function showTip(oEvent) {
        var oDiv = document.getElementById("toolTipComponent");
        oDiv.style.visibility = "visible";
        oDiv.style.left = oEvent.clientX + 5;
        oDiv.style.top = oEvent.clientY + 5;
    }

    function hideTip(oEvent) {
        var oDiv = document.getElementById("toolTipComponent");
        oDiv.style.visibility = "hidden";
    }
</script>
</head>
<body>
<P>Move your mouse over the hyper link.</p>
<a href="http://www.java2s.com"
   onmouseover="showTip(event)" onmouseout="hideTip(event)">www.java2s.com</a>

<div id="toolTipComponent" style="background-color: green; position: absolute; visibility: hidden; padding: 5px">
<span style="font-weight: bold">Custom Tooltip</span><br/>
detail information for www.java2s.com
</div>

</body>
</html>

28.4.Tooltips
	28.4.1.	Tooltips based on div