req.flash('error', '') 没有效果如何解决

app.js

var flash = require('connect-flash');

app.use(flash());

app.use(function(req, res, next) {
    res.locals.errors = req.flash('error');
    res.locals.infos = req.flash('info');
    next();
});

reg.jade

extends layout

block content
  include left.jade
  .row.right.col-lg-6
    form.form-horizontal(method="post")
      .err.col-lg-offset-2.text-center #{errors} 
      .form-group
        label.col-lg-2.text-right(for="user1") 用户名:
        .col-lg-10
          input.user.form-control(type='text',placeholder="用户名",name="name",)  
      br
      .form-group
        label.col-lg-2.text-right(for="1") 密码:
        .col-lg-10
          input.password.form-control(type='password',placeholder="密码",name="password",)    
      br
      .form-group
        label.col-lg-2.text-right(for="1") 确认密码:
        .col-lg-10
          input.password.form-control(type='password',placeholder="确认密码",name="password_re",)     
      br
      .form-group
        label.col-lg-2.text-right(for="1") 邮箱:
        .col-lg-10
          input.email.form-control(type='email',placeholder="[email protected]",name="email",)    
      br
      .col-lg-10.col-lg-offset-2

        input(type="submit",value="注册")

reg.js

var router = require('express').Router();


var crypto = require('crypto'),
    User = require('../models/user.js');


router
    .get('/', function(req, res, next) {
        res.render('reg', { title: '注册' });
    })
    .post('/', function(req, res) {
        var name = req.body.name,
            password = req.body.possword,
            // pasword_re = req.body['password-repeat'];
            password_re = req.body.password_re;
        if (password_re != password) {
            req.flash('error', '两次输入的值如一样');
            return res.redirect('/reg'); //返回注册的首页
        }
        var md5 = crypto.createHash('md5'),
            password = md5.update(req.body.password).digest('hex');
        var newUser = new User({
            name: req.body.name,
            password: req.body.password,
            email: req.body.email
        });
        User.get(newUser.name, function(err, user) {
            if (user) {
                req.flash('error', '用户已存在');
                return res.redirect('/reg');
            }
            newUser.save(function(err, user) {
                if (err) {
                    req.flash('error', err);
                    return res.redirect('/reg');
                }
                req.session.user = user;
                req.flash('success', '注册成功');
                res.redirect('/');
            });
        });
    });
module.exports = router;