Untitled

var http = require('http');
var fs   = require('fs');
var io = require('socket.io');

var server = http.createServer(function(req,res){
    res.writeHead(200,{'Content-Type' : 'text/html'});
    fs.readFile('./index.html',function(err,content){
        res.end(content);
    });

}).listen(8080);

io = io.listen(server)

io.sockets.on('connection',function(client){

client.emit('connecte');

});

<html>
    <meta charset='utf-8'/>
    <head>
        <title>my first page</title>
    <script src="http://localhost:8080/socket.io/socket.io.js" ></script>
    </head>
    <body>
        <h1>It work</h1>
    </body>
    <script>
    var socket;

    socket = io.connect('http://localhost:8080');

    socket.on('connecte', function(){
            alert('You are connected');
        });

    </script>
</html>