Eccolo qua
<script language="javaScript1.1">
<!-- Begin
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("Spiacenti, il tasto destro del mouse e' disabilitato");
return false;
}
return true;
}
document.onmousedown=right;
if (document.layers) window.captureEvents(Event.MOUSEDOWN);
window.onmousedown=right;
// End -->
</script>