title: mongodb in nodejs return undefined when trying to connect to collection
body: <p>when I write this code below I get:</p>
  
  <pre><code>Connected correctly to DB
  undefined 
  undefined 
  </code></pre>
  
  <p>I have collection named users, so this sould not happened... why is the happening?</p>
  
  <p>Thanks</p>
  
  <pre><code>var url = 'mongodb://user:pass@ds023475.mlab.com:23475/small-talkz';
  MongoClient.connect(url, function(err, db) {
  
      if (err) {
          console.log(err);
          return db.close();
      }
  
      console.log("Connected correctly to DB.");
      // update a record in the collection
      console.log(db.collection("users"));
      console.log(db.users); 
  
      return db.close();
  });
  </code></pre>