[jquery] How to get value in the session in jQuery

Sessions are stored on the server and are set from server side code, not client side code such as JavaScript.

What you want is a cookie, someone's given a brilliant explanation in this Stack Overflow question here: How do I set/unset cookie with jQuery?

You could potentially use sessions and set/retrieve them with jQuery and AJAX, but it's complete overkill if Cookies will do the trick.