Help your users to upgrade their outdated browsers
There are a lot of users that come on your website and are unable to navigate it properly because of their browser (Specially internet explorer previous versions). You personally can’t ask or direct anyone to upgrade their browsers but there’s a small script that helps/notifys them to do so. It’s called “Pushup” a small package that you can install on your server, including the Pushup CSS and javascript file in your header and adding a small code on your website (as mentioned)
<link rel='stylesheet' type='text/css' href='css/pushup.css' /> <script type='text/javascript' src='js/pushup.js'></script>

Pushup currently supports 4 browsers, Internet explorer, FireFox, Safari and Opera. There are also customizable options that you can set according to your requirements like delays, reminder messages etc.
Official website: Pushup