php – 在一个页面与codeigniter会话库之间丢失会话变量

<?php   
 public function carconfirm($car_id = '')
        {

            if(empty($car_id))
            {
                redirect('welcome');
            }

            $this->load->model('mcars');
            $car = $this->mcars->getCar($car_id);

            $data['car'] = $car->row_array();


            $car_id = (int) $car_id;
            $this->session->set_userdata('flappy',$car_id);
            echo $car_id;



            //insert details 
            //display details

            $this->load->view('phps/carconfirm',$data);
        }

        function confirm()
        {

            //get vars

            $time_slot = $this->session->userdata('slot');
            $person_id = $this->session->userdata('person_id');
            $car_id = $this->session->userdata('flappy');

            $insert_array = array(  'slot'=> $time_slot,'car'=> $car_id,'person_id'=> $person_id
                                );
            print_r($insert_array);

            $this->load->model('mbooking');
            $result = $this->mbooking->addbooking($insert_array);

            if($result)
            {
                redirect('welcome/options');
            }

        }
?>

我失去的变量是flappy-我更改了名称以查看是否存在问题