node.jsで簡単なexpressアプリを作る

http://www.youtube.com/watch?v=A2OKXxAMqcs
server.js

var fs = require("fs");
var config = JSON.parse(fs.readFileSync("config.json"));
var host = config.host;
var port = config.port;
console.log(host);
console.log(port);
var express = require("express");
var app = express();
app.use(app.router);
app.use(express.static(__dirname + "/public"));

app.get("/",function(request,response){
    response.end("hello");
});
app.get("/hello/:text",function(request,response){
    response.send("Hello " + request.params.text);
});
//users                                                                           
var users = {
    "1": {
            "name":"Osley",
            "twitter":"hoge"
    },
    "2": {
            "name":"Jeff",
            "twitter":"foobar"
        }
};
app.get("/user/:id",function(request,response){
    var user = users[request.params.id];
    if(user){
        response.send("Hello "+ user.name + "<br />" +
                      "Your twitter account is " + user.twitter);
    } else {
        response.send("Sorry the user not found",404);
    }
});
app.listen(port,host);

config.json

{
        "host" : "127.0.0.1",
        "port" : 1337
}