Disabilitare il tasto destro del mouse

<script language="JavaScript1.2">
<!-- Start
/* prelevato su web-link: http://www.web-link.it */

function right(e) {
if (navigator.appName == 'Netscape' &&
(e.which == 3 || e.which == 2))
return false;
else if (navigator.appName == 'Microsoft Internet Explorer' &&
(event.button == 2 || event.button == 3)) {
alert("Inserisci qui il tuo messaggio di alert");
return false;
}
return true;
}
document.onmousedown=right;
if (document.layers) window.captureEvents(Event.MOUSEDOWN);
window.onmousedown=right;

// end -->
</script>