Model is loaded but I get error.

Code:
&lt;?php 

class Testimonials extends CI_Controller

{



public $data = array();

/*============*/

// constructor

/*============*/

function __construct()

{

 parent::__construct();

 

 $this->load->model('admin/admin_model');



 

 if(!$this->admin_model->validate_session())

  {

   die('you do not have permission');

  }

 else {

  

  //load required models

  $this->load->model('admin/testimonials_config_model');

  $this->load->model('admin/testimonials_model');

  //initialize variables

  $this->data['change_settings'] = FALSE;

  $this->data['atleast_one_required_field'] = TRUE;

  $this->data['testimonials_p_p_error'] = FALSE;

 }







}







/*=========*/

// manage 

/*=========*/

public function manage($action = null, $id = null) {









$this->data['deleted'] = false;



if(strcasecmp($action, 'delete') == 0 )

{

 $this->db->delete('nv_cms_testimonials',array('id'=>$id));

 $this->data['deleted']=true;

 

 $this->data['testimonials'] = $CI->testimonials_model->get_all_testimonials();

 $this->load->view('admin/testimonials_manage_view',$this->data);



}

elseif(strcasecmp($action, 'edit')==0)

{

 

 

 $this->data['testimonial'] = $CI->testimonials_model->get_testimonial_by_id($id);

 $this->load->view('admin/testimonials_edit_view',$this->data);

}

elseif(strcasecmp($action, 'update')==0)

{

 $CI->testimonials_model->update_testimonial($id);

 

}else{





 

 

 $this->data['testimonials'] = $this->testimonials_model->get_all_testimonials_with_pagination('5',$this->uri->segment(4));

 

 //pagination

 $this->load->library('pagination');

 $config['base_url'] = base_url().'admin/testimonials/manage';

 $config['total_rows'] = $CI->testimonials_model->get_all_testimonials;

 $config['per_page'] = 5;

 $this->pagination->initialize($config); 

 

 

 $this->load->view('admin/testimonials_manage_view',$this->data);

 }

 

}//manage



}