Puoi provare questo (non troppo testato)

codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<head>
<title>Untitled</title>
<script language="JavaScript" type="text/javascript">
<!--
function mouseCoord(obj) {
 //----- X
 pX = obj.offsetLeft;
 aX = event.x;
 aX = aX - pX;
 //----- X
 pY = obj.offsetTop;
 aY = event.y;
 aY = aY - pY; 
 window.status = ""+pX+"x="+aX+" - y="+aY;
} // function mouseCoord(obj) 
//-->
</script>

</head>
<body>




<div align="center" >
[img]images_3/file6.jpg[/img]
</div>
</body>
</html>