Con l'esadecimale

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

<html>
<head>
<title>Untitled</title>
</head>
<body>
<script language="JavaScript" type="text/javascript">
<!--
function pippo(unaStringa) {
 len    = unaStringa.length;
 result = '';
 for (i=0;i<len;i++) {
  car     = unaStringa.charCodeAt(i);
	result += decToHex(car);
 } // for (i=0;i<len;i++)
 return result;
} // function pippo(unaStringa)

function decToHex(aValue) {
 hexStr = '0123456789ABCDEF';
 if (parseInt(aValue/16) == 0) {
  return hexStr.charAt(aValue % 16);
 }
 return decToHex(parseInt(aValue/16))+hexStr.charAt(aValue % 16);
}
alert(pippo("ABCD")); 
//alert(decToHex(255666666))
//-->
</script>

</body>
</html>