You should use e.charCode
in Firefox.
$("#booter").keypress(function(e){
var code = e.charCode || e.keyCode;
var input = $(this).val() + String.fromCharCode(code);
$('#text').focus().val(input);
return false;
});
Try it here:
PS
If you’re wondering why all this mess: http://www.quirksmode.org/js/keys.html