old_contents: 
  /**
   * Module dependencies.
   */
  
  var express = require('express');
  var routes = require('./routes');
  var user = require('./routes/user');
  var http = require('http');
  var path = require('path');
  
  var signin = require('./routes/signin');
  var signup = require('./routes/signup');
  var feed = require('./routes/feed');
  var signout = require('./routes/signout');
  var index = require('./routes/index');
  var notFound = require('./routes/notFound');
  var internalError = require('./routes/internalError');
  var bulk = require('./routes/bulk');
  var upload = require('./routes/upload');
  
  var app = express();
  
  // all environments
  app.set('port', process.env.PORT || 8250);
  app.set('views', path.join(__dirname, 'views'));
  app.set('view engine', 'jade');
  app.use(express.favicon());
  app.use(express.logger('dev'));
  app.use(express.json());
  app.use(express.urlencoded());
  app.use(express.multipart());
  app.use(express.methodOverride());
  app.use(express.cookieParser('S3CRE7'));
  app.use(express.cookieSession());
  app.use(app.router);
  app.use(express.static(path.join(__dirname, 'public')));
  app.use(function(req, res, next){
  	res.status(404).redirect('/notFound');
  });
  app.use(function(req, res, next){
  	res.status(500).redirect('/internalError');
  });
  
  // development only
  if ('development' == app.get('env')) {
    app.use(express.errorHandler());
  }
  
  app.get('/', routes.index);
  app.get('/sessions/new', index.formSignIn);
  app.get('/users/new', index.formSignUp);
  app.post('/signin', signin.signin);
  app.post('/users/create', signup.signup);
  app.post('/signup', signup.signup);
  app.get('/users', user.list);
  app.get('/feed',feed.feed);
  app.get(/\/feed?page=\d+/,feed.feed);
  app.get('/photos/new',upload.newPicture)
  app.post('/photos/create',feed.upload)
  app.get(/users\/\d+\/follow/, user.follow)
  app.get(/users\/\d+\/unfollow/, user.unfollow)
  app.get(/\/users\/\d+/, feed.stream);
  app.get('/signout',signout.signout);
  app.get('/notFound',notFound.notFound);
  app.get('/internalError', internalError.internalError);
  app.get('/bulk', bulk.bulk);
  app.get('/bulk/clear?password=:password', bulk.clear);
  app.post('/bulk/users?password=:password', bulk.users);
  app.post('/bulk/streams?password=:password', bulk.streams);
  
  
  http.createServer(app).listen(app.get('port'), function(){
    console.log('Express server listening on port ' + app.get('port'));
  });
  
new_contents: 
  /**
   * Module dependencies.
   */
  
  var express = require('express');
  var routes = require('./routes');
  var user = require('./routes/user');
  var http = require('http');
  var path = require('path');
  
  var signin = require('./routes/signin');
  var signup = require('./routes/signup');
  var feed = require('./routes/feed');
  var signout = require('./routes/signout');
  var index = require('./routes/index');
  var notFound = require('./routes/notFound');
  var internalError = require('./routes/internalError');
  var bulk = require('./routes/bulk');
  var upload = require('./routes/upload');
  
  var app = express();
  
  // all environments
  app.set('port', process.env.PORT || 8250);
  app.set('views', path.join(__dirname, 'views'));
  app.set('view engine', 'jade');
  app.use(express.favicon());
  app.use(express.logger('dev'));
  app.use(express.json());
  app.use(express.urlencoded());
  app.use(express.multipart());
  app.use(express.methodOverride());
  app.use(express.cookieParser('S3CRE7'));
  app.use(express.cookieSession());
  app.use(app.router);
  app.use(express.static(path.join(__dirname, 'public')));
  app.use(function(req, res, next){
  	res.status(404).redirect('/notFound');
  });
  app.use(function(err, req, res, next){
  	res.status(500).redirect('/internalError');
  });
  
  // development only
  if ('development' == app.get('env')) {
    app.use(express.errorHandler());
  }
  
  app.get('/', routes.index);
  app.get('/sessions/new', index.formSignIn);
  app.get('/users/new', index.formSignUp);
  app.post('/signin', signin.signin);
  app.post('/users/create', signup.signup);
  app.post('/signup', signup.signup);
  app.get('/users', user.list);
  app.get('/feed',feed.feed);
  app.get(/\/feed?page=\d+/,feed.feed);
  app.get('/photos/new',upload.newPicture)
  app.post('/photos/create',feed.upload)
  app.get(/users\/\d+\/follow/, user.follow)
  app.get(/users\/\d+\/unfollow/, user.unfollow)
  app.get(/\/users\/\d+/, feed.stream);
  app.get('/signout',signout.signout);
  app.get('/notFound',notFound.notFound);
  app.get('/internalError', internalError.internalError);
  app.get('/bulk', bulk.bulk);
  app.get('/bulk/clear?password=:password', bulk.clear);
  app.post('/bulk/users?password=:password', bulk.users);
  app.post('/bulk/streams?password=:password', bulk.streams);
  
  
  http.createServer(app).listen(app.get('port'), function(){
    console.log('Express server listening on port ' + app.get('port'));
  });
  
subject: handle 500 error correctly !