Real time events when I click on div with node.js and socket.io

I´m making a simple real time application.

I have a page with a square and when I click the square is painted or remove the paint.

I want make the event in one tab and see his effect in other tab.

I dont have too much experience with node.js and socket.io

There is my server:

    var sock = require('socket.io')
    , express = require('express')
    , path = require('path')
    var app = express();

    app.configure(function(){
      app.set('views', __dirname + '/views');
      app.set('view engine', 'jade');
      app.use(express.cookieParser());
      app.use(express.static(path.join(__dirname, 'public')));
     });

    app.get('/', function (req,res) {
       io.sockets.in(req.sessionID);
       res.render(__dirname + '/views/teste.jade');
    });

    io = sock.listen(app.listen(3000));

    io.sockets.on('connection', function(socket){ 
      var sess = socket.handshake.session;
      socket.on('hasClass', function(data) {
         socket.emit('hasClass', {hasClass: data.hasClass})
      });
    });

And there is my .jade:

    doctype 5
      html
        head
          title= "Express"
          link(rel='stylesheet', href='/stylesheets/style.css')
          script(src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js")
          script(src="/socket.io/socket.io.js")
          script
          $(document).ready(function() {
             var socket = io.connect('http://localhost:3000');
             socket.on('connect', function(){
               $('#quadrado').click(function() {
                 if ($('#quadrado').hasClass('clicked')) {
                   socket.emit('hasClass', {hasClass:true});
                 } else {
                   socket.emit('hasClass', {hasClass:false});
                 }
               });
            });

            socket.on('hasClass', function(data){
              if(data.hasClass) {
                $('#quadrado').removeClass('clicked');
              } else {
                $('#quadrado').addClass('clicked');
              }
            });
         });
       body
         block content