Client

<!DOCTYPE html>
<html>
<body>
<section id="affichage">

        </section>

        <script src="/socket.io/socket.io.js"></script>
        <script>
        var socket = io.connect('http://localhost:8080');
        socket.on('message', function(message) {
                $('#affichage').prepend('<p><em>'+message+'</em></p>');
            })

</script>
<form method="POST" action="http://localhost:8080">
<input type="submit" name="ON" value="ON" >
</form>

</body>
</html>