'node-formidable' file upload problems when using Express framework

I am trying to perform file upload using formidable module. I followed their example and it works well, when i do the same using express module, i dont get it working. It hungs there, after the log i kept in POST /upload.

This is the link for sample. https://github.com/felixge/node-formidable/blob/master/example/upload.js

I think it is something to do with the 'uploadDir' value. I have given current directory('/') as the directory lookup to express, and i expected the files uploaded to be present in files folder in the current directory, from where node is run. Donno where it is getting stuck ? any help is appreciated...!! Thanks,

var formidable = require('formidable'),
http = require('http'),
util = require('util');
connectTimeout = require('connect-timeout');
mongoose = require('mongoose');
express = require('express');
app = express();
server = http.createServer(app);

server.listen(4000);

app.configure(function(){
app.set('views', __dirname + '/views');
app.use(express.favicon());
app.use(connectTimeout({ time: 20000 }));
app.use(express.methodOverride());
app.use(express.bodyParser());
app.use(express.static(__dirname + '/'));
});

app.get('/',function(req, res) {

res.writeHead(200, {'content-type': 'text/html'});
res.end(
'<form action="/upload" enctype="multipart/form-data" method="post">'+
'<input type="text" name="title"><br>'+
'<input type="file" name="upload" multiple="multiple"><br>'+
'<input type="submit" value="Upload">'+
'</form>'
);
});

app.post('/upload', function(req,res) {

console.log(" ########## POST /uplaod ####### "+ req.files+" :: "+__dirname);
var form = new formidable.IncomingForm(),
files = [],
fields = [];
form.uploadDir = __dirname+"/files";

form.on('field', function(field, value) {
    fields.push([field, value]);
})
form.on('file', function(field, file) {
    console.log(file.name);
    files.push([field, file]);
})
form.on('end', function() {
    console.log('done');
    res.redirect('/forms');
});
form.parse(req);

});