CodeIgniter（2.1.0）致命错误::调用未定义的方法Paidlisting_model :: ls（）

Question

第16行$data['paidls']=$this->paidlisting->ls();抛出错误调用未定义的方法。我在这里粘贴了我的控制器和模型。

控制器| package.php

<?php
class Package extends CI_Controller{
public function __construct(){
parent::__construct();
    $this->load->model('advertise/advertise_model','advertise');
    $this->load->model('advertise/package_model','package');
    $this->load->model('advertise/paidlisting_model','paidlisting');
    $this->load->model('gallery/gallery_model','gallery');
    $this->load->model('log','log');
    $this->load->library('payment');
    $myself = $this->session->userdata('client');
    }
    public function index(){
      $data = array();
       $data['banners']=$this->package->ls();
      $data['paidls']=$this->paidlisting->ls();
       $this->load->library('media');
       foreach($data['banners'] as $key=>$banner)
       {
         if($this->gallery->fetchAllData('adv_package',$banner->id)){
           $images = array();
              $imgs = $this->gallery->fetchAllData('adv_package',$banner->id);
              foreach ($imgs as $im)
              {
                $images[] =array(to_imageurl($im),'alt'=>$im->alt);
              }
              $data['banners'][$key]->image = $images;

          }else{
                  $data['banners'][$key]->image = '';
          }
       }    
       foreach($data['paidls'] as $key=>$row)
       {
         if($this->gallery->fetchAllData('adv_paidlisting_package',$row->id))
         {
           $images = array();
              $imgs = $this->gallery->fetchAllData('adv_paidlisting_package',$row->id);
              foreach ($imgs as $im)
              {
                $images[] =array(to_imageurl($im),'alt'=>$im->alt);
              }
              $data['paidls'][$key]->image = $images;

          }else{
                  $data['paidls'][$key]->image = '';
          }
       }

型号| paidlisting_model.php

 public function ls(){

$result = $this->db->get_where('adv_paidlisting_package',array('status'=>1));

  $data = array();

      if($result->num_rows()){

          foreach($result->result() as $item){

            array_push($data,$item);

          }

      }

    return $data;  

  }

请帮我解决。