Can't retrieve data from mongoDB with Node.js

I'm pretty new in Node.js and I have this project. Basically I have some data sits in a mongoDB collection("data") and I'm trying to get that data and display it on the browser.

Here is what I've got so far;

    var MongoClient = require('mongodb').MongoClient
        ,format = require('util').format;
    var sys = require ("sys");
    my_http = require("http");

      my_http.createServer(function(request, response){
         sys.puts("Touched !!");
         response.writeHeader(200, {"Content-Type": "text/plain"});
         response.write(extractData()).toString();
         response.end();
     }).listen(8080);
sys.puts("Server is running on 8080"); // Server kicks in...np

function extractData(){

    MongoClient.connect('mongodb://127.0.0.1:27017/mongoDB', function(err, db){
        if (err){
            console.log("Can't Connect to DB !!");
        }else {
            console.log("Connected to DB !!");   // connects to DB, np
            db.data.find({}, function(err, data){  // .find is the problem
                if (err || !data) console.log("No Data Found");
                else data.forEach(function (data){
                    console.log(data);
                });
            }).toArray();
        }
    });
}

And after I run "node server.js" and refresh the already open localhost:8080, I get this;

Server is running on 8080
Touched !!
Touched !!
Connected to DB !!

d:\Projects\SCRIPTS\mdp.scripts.testing-tools\jsFinderWmongoDB\node_modules\mongodb\lib\mongodb\mongo_client.js:475
          throw err
                ^
TypeError: Cannot call method 'find' of undefined
    at d:\Projects\SCRIPTS\mdp.scripts.testing-tools\jsFinderWmongoDB\server.js:21:21
    at d:\Projects\SCRIPTS\mdp.scripts.testing-tools\jsFinderWmongoDB\node_modules\mongodb\lib\mongodb\mongo_client.js:4
72:11
    at process._tickCallback (node.js:415:13)

Don't understand why there is a problem with .find() and of course can't display any data...

Any ideas?