public function loginAction()
    {
        $this->view->message = '';
        $this->view->title = 'Log in';

        if ($this->_request->isPost()) {

            // collect the data from the user
            Zend_Loader::loadClass('Zend_Filter_StripTags');
            $f = new Zend_Filter_StripTags();
            $username = $f->filter($this->_request->getPost('usuarios_usuario'));
            $password = $f->filter($this->_request->getPost('usuarios_senha'));

            //pr($this->_request->getPost());

            if (empty($username)) {

                $this->view->message = 'Please provide a username.';

            } else {

                // setup Zend_Auth adapter for a database table
                Zend_Loader::loadClass('Zend_Auth_Adapter_DbTable');
                $db = Zend_Registry::get('db');
                $authAdapter = new Zend_Auth_Adapter_DbTable($db);
                $authAdapter->setTableName('usuarios');
                $authAdapter->setIdentityColumn('usuarios_usuario');
                $authAdapter->setCredentialColumn('usuarios_senha');
                // Set the input credential values to authenticate against
                $authAdapter->setIdentity($username);
                $authAdapter->setCredential($password);
                // do the authentication
                $auth = Zend_Auth::getInstance();
                $result = $auth->authenticate($authAdapter);

                if ($result->isValid()) {

                    // success: store database row to auth's storage
                    // system. (Not the password though!)
                    $data = $authAdapter->getResultRowObject(null,'password');
                    $auth->getStorage()->write($data);
                    $this->_redirect('/');

                } else {

                    // failure: clear database row from session
                    $this->view->message = 'Login failed.';

                }
            }
        }
    }