Header Location for Users With No Access

Well, ive been thinking about it and have finally decided to suggest this feature......maybe instead of displaying no forums to users that have no permission to them you could redirect them to login.php? I think it suits the forums better than displaying a no access message.

For now im currently redirecting all guests to login.php with this:

if ( $pun_user['is_guest'] )
header("location: login.php");

Im sure this would be a great feature if you were to modify this code to make it so that only if the guests have no access to the boards this code would take effect.