Why I get the error 'Call to undefined function delete_cookie ()' on Codeigniter?

     

I think the code that I run is correct but a moment in the run even appear error 'Call to undefined function delete_cookie ()'


Please for correction :)


in Controller Product_Ref.php


public function index()   {   $ref = $this->input->get('id');   $getIdOrder = $this->product_model->getIdOrder($ref);   if ($getIdOrder) {   $this->load->helper('cookie');   $cookie = array(   'name' => 'refProductcookie'   'value' => $ref