codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<style type="text/css">
#idDiv {
	position:absolute;
	width:100px;
	height:100px;
	background:orange;
}
</style>
<script type="text/JavaScript">
/*<![CDATA[*/
function getKeyCode(e,step){
	var key=(e.which)?e.which:e.keyCode;
	var dS=document.getElementById('idDiv').style;
	switch(key){
		case 37:dS.left=(parseInt(dS.left)-step)+'px';break;
		case 38:dS.top=(parseInt(dS.top)-step)+'px';break;
		case 39:dS.left=(parseInt(dS.left)+step)+'px';break;
		case 40:dS.top=(parseInt(dS.top)+step)+'px';break;
	}
}
/*]]>*/
</script>
</head>
<body onkeydown="getKeyCode(event,5)">
<div id="idDiv" style="top:100px;left:100px"></div>
</body>
</html>