formidable is not working in node.js

I am using formidable package to parse a form in node.js to upload a file. When i trying to triggering form.parse() method it is not working properly.

This is my server side code.

var formidable = require('formidable'),
http = require('http'),
util = require('util');
console.log("Before parsing");
var form = new formidable.IncomingForm();
form.parse(req, function(err, fields, files) {
console.log(util.inspect({fields: fields, files: files}));
});
return;

Please give some suggestions.