WooCommerce - Change page title when tab is not active - wordpress

Question

I am looking for function for WooCommerce which change meta title text in non-active tab. Anybody know how can I do it? I find this JS code but it does not work in themes function.php file:
$(function() {
var message = "Don't forget us";
var original;
$(window).focus(function() {
if (original) {
document.title = original;
}
}).blur(function() {
var title = $('title').text();
if (title != message) {
original = title;
}
document.title = message;
});
});

Answer 1

The following goes into functions.php
add_action('wp_head', function () {
?>
<script>
(function () {
var message = "Don't forget us"
var original
jQuery(window).on("focus", function () {
if (original) {
document.title = original
}
}).on("blur", function () {
var title = jQuery("title").text()
if (title != message) {
original = title
}
document.title = message
})
})()
</script>
<?php
});

Answer 2

You can put that script into a tag <script></script> in the footer.php file wich should be located in your theme (don't forget to actually duplicate this file inside your child theme)
EDIT: Also make sur to have JQuery in your frontend