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(aCB) {
prefix = aCB.id.substr(0,3);
if (prefix+'S' == aCB.id) {
document.getElementById(prefix+'N').checked = ! aCB.checked;
} else {
document.getElementById(prefix+'S').checked = ! aCB.checked;
}
}
//-->
</script>
</head>
<body>
<input type="checkbox" id="cb1S" onclick="pippo(this)">Si
<input type="checkbox" id="cb1N" onclick="pippo(this)">No
</body>
</html>