NodeJS - HTML version of basic "todo" server

node_html_todo.js

var http = require('http'),
  qs = require('querystring'),
  items = [];

var server = http.createServer(function(req, res){
  if('/' == req.url){
    switch(req.method){
      case 'GET':
        show(res);
        break;
      case 'POST':
        add(req, res);
        break;
      default:
        badRequest(res);
    }
  } else {
    notFound(res);
  }
}).listen(3000);

function show(res) {
  var html = '<h1>Todo List</h1>'
              + '<ul>'
              + items.map(function(item){
                return '<li>' + item + '</li>'
              }).join('')
              + '</ul>'
              + '<form method="post" action="/">'
              + '<p><input type="text" name="item" /></p>'
              + '<p><input type="submit" value="Add Item" /></p>'
              + '</form>';
  res.setHeader('Content-Type', 'text/html');
  res.setHeader('Content-Length', Buffer.byteLength(html));
  res.end(html);
};

function notFound(res) {
  res.statusCode = 404;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Not Found');
};

function badRequest(res) {
  res.statusCode = 400;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Bad Request');
};

function add(req, res){
  var body = '';
  req.setEncoding('utf8');
  req.on('data', function(chunk){body += chunk});
  req.on('end', function(){
    var obj = qs.parse(body);
    items.push(obj.item);
    show(res);
  });
};