[fw-mvc] zf can not autoload models and forms

I create a project, the application directory looks like this:

application:

controllers

configs

models

User.php---- class Model_User

forms

User.php---- class Form_user

vies

bootstrap.php

When I try to use Model_User or Form_User class, error occurs that class can not be found!

How to make them autoloaded?

--
Location: