Server chat with Node.js and Socket.IO

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);

//Include .html file
app.get('/', function(req, res) {
    //res.send('<h1>Hello World</h1>');
    res.sendFile(__dirname + '/index.html');
});

io.on('connection', function(socket) {
    //User connected
    console.log('a user connected');
    //User disconnected
    socket.on('disconnect', function() {
        console.log('user disconnected');
    });
    //Show message send from user
    socket.on('chat message', function(msg) {
        console.log('message: ' + msg);
        //Broadcast message to all user
        io.emit('chat message', msg);
    });
});

//Listen port 3000
http.listen(3000, function() {
    console.log('listening on *:3000');
});