Puoi fare cosi....
codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Untitled</title>
<script language="JavaScript" type="text/javascript">
<!--
function pippo(e) {
mioTesto = document.getElementById('testo').value;
document.getElementById('d').innerHTML = mioTesto;
if (e == null) {
if (event.keyCode == 46) {
event.keyCode = 42
} // if (event.keyCode == 46)
} else {
if (e.which == 46) {
var newEvent = document.createEvent("KeyEvents")
newEvent.initKeyEvent("keypress", true, true, document.defaultView,
e.ctrlKey, e.altKey, e.shiftKey,
e.metaKey, 0, "*".charCodeAt(0))
e.preventDefault()
e.target.dispatchEvent(newEvent)
} // if (e.which == 46)
} // if (window.event != null)
//document.getElementById('testo').value = mioTesto;
}
//-->
</script>
</head>
<body>
<input type="text" size="30" id="testo">
<div id="d"></div>
<script language="JavaScript" type="text/javascript">
<!--
//--------- Assegnazione dell'evento onkeypress del text box
document.getElementById('testo').onkeypress = pippo;
//-->
</script>
</body>
</html>
E dopo c'è chi si lamenta di IE !!!!
La parte per FF l'ho trovata qua