$js->property_by_path("document.location.href");
$js->property_by_path("window");
$js->property_by_path("navigator.userAgent");
$js->property_by_path("navigator.appVersion");
$js->function_set("toLowerCase", sub {return lc($_[0]); });
$js->function_set("javaEnabled", sub {undef});

##</code><code>##

$js->property_by_path.....
$js->function_set.....