node.js - expressjs socket.io port 3000 is already in use -

should need to specify different ports express (3000) , socket.io?

error: port 3000 in use

my code:

index.js

var express = require('express') ,router = express.router()   , app = express()   , http = require('http')   , server = http.server(app)   , io = require('socket.io').listen(server)  server.listen(3000);  router.get('/', function(req, res, next) {   res.render('index', { title: 'express' }); });   io.on('connection',function(socket){       console.log("a user connected");      socket.on('point1', function (value) {         socket.broadcast.emit('point1',value);     });      socket.on('less1', function (value) {         socket.broadcast.emit('less1',value);     });      socket.on('point2', function (value) {         socket.broadcast.emit('point2',value);     });      socket.on('less2', function (value) {         socket.broadcast.emit('less2',value);     }); });  module.exports = router; 

index.html

<script src="/socket.io.js"></script> <script type="text/javascript"> var socket = io.connect(); </script> 

or how can pass variable on io.connect("use-host:use-port");

on index.html app.js or config file.