old_contents: var http = require('http'),
      app  = require('./app');
  
  http.createServer(app).listen(app.get('port'), function () {
      console.log(app.get('name') + ' Server listening on ' + app.get('port'));
  });
  
new_contents: var http = require('http'),
      app  = require('./app'),
      port = app.get('port');
  
  http.createServer(app).listen(port, function () {
      console.log(app.get('name') + ' Server listening on ' + port);
  });
  
subject: Improve readability of server.js.