funziona funziona, prova
codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
      "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title></title>
<style type="text/css">
#box {
	position:absolute;
	top:0px;
	left:0px;
	z-index:100;
	visibility:hidden;
	width:136px;
	background-color:#099;
	color:#fff;
	padding:3px;
}
</style>
<script type="text/javascript">
<!--

function getPageCoords(el) {
	var coords = {x: 0, y: 0}; 
	while (el) { 
		coords.x += el.offsetLeft; 
		coords.y += el.offsetTop; 
		el = el.offsetParent; 
	} 
	return coords; 
} 

function mostra(el){
	var p=getPageCoords(el);
	var lvl=document.getElementById('box');
	lvl.style.top=p.y+20+'px';
	lvl.style.left=p.x+'px';
	lvl.innerHTML='^ inserisci il '+el.id;
	lvl.style.visibility='visible';
}
function nascondi(){
	document.getElementById('box').style.visibility='hidden';
}
//-->
</script>
</head>
<body>
<div id="box"></div>
<form>
<input type="text" id="nome" onfocus="mostra(this)" onblur="nascondi()" />
<input type="text" id="cognome" onfocus="mostra(this)" onblur="nascondi()" />
</form>
</body>
</html>