index.html

<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>User Application</title>
    </head>
    <body>
        <div id="app"></div>

        <!-- plugin initialization -->
        <script>
            document.addEventListener('DOMContentLoaded', function(){
                // create instance of a plugin
                var elem = document.getElementById('app');
                var instance = new UserList(elem, [
                    {firstname: 'Ross', lastname: 'Geller'},
                    {firstname: 'Monica', lastname: 'Geller'},
                    {firstname: 'Chandler', lastname: 'Bing'},
                    {firstname: 'Joey', lastname: 'Tribbiani'},
                ]);

                // initialize
                instance.init();

                // add new users
                setTimeout(function(){
                    instance.addUser({firstname: 'Rachel', lastname: 'Green'});

                    setTimeout(function(){
                        instance.addUser({firstname: 'Phoebe', lastname: 'Buffay'});
                    }, 2000);
                }, 2000);
            });
        </script>
    </body>
</html>