jQuery is almost ubiquitous when it comes to JavaScript libraries, and we will use it in our application too. To add jQuery to our application, let's download the latest release from http://www.jquery.com/ and save it to public/javascript/jquery.min.js. Then, we add the script in layout.jade to pull in jQuery to our application's pages:

    script(type='text/javascript', src='/javascripts/jquery.min.js')