Validate the navigator version that's being used to access the website.

First of all, you must import the JavaScript file to your page:

<script src="Navigator.js" type="text/javascript"></script>

And then, use the main function to test the navigator version:

if (!$.Navigator().test()) {
    alert('Update your browser!');
}

You can easily specify the minimum version supported:

if (!$.Navigator().test({ chrome: 40 })) {
    alert('Update your browser!');
}