newb node.js mongo write to browser

I'm trying to get my head around node's connection to mongo via MongoClient. As Far As I Can Tell I'm connecting to Mongo and pulling data and encoding it to JSON. This is not shown in the example bellow as I haven't been able to output the data to the browser while node is still running. I've stripped out everything so as to just present the problem. In code bellow "the connection" is logged to the console but then the browser hangs. If I shut down the node instance then "wtf" is written to the browser window. I'm a node newb so thanks for any help.

var http = require("http");
var MongoClient = require('mongodb').MongoClient;

start();

function start() {
    function onRequest(request, res) {
        console.log("request");
        var mongoclient = MongoClient.connect("mongodb://localhost:27017/first", function(err, db) {
            if(!err) {
                console.log("the connection");
                res.writeHead(200, {"Content-Type": "text/plain"});
                res.write("wtf");
                res.end;
            } else {
                console.log(err);
            }
        });
    }
    http.createServer(onRequest).listen(1337, '127.0.0.1');
    console.log('Server running at http://127.0.0.1:1337/');
}