ga bisa error coedigneter

//ini bagian model untuk memasukkan data

public function set_news(){ $this->load->helper('url');

$slug->url_title($this->input->post('title'),'dash',TRUE); //error

$data=array( 'title'=>$this->input->post('title'), 'text'=>$this->input->post('text'), 'slug'=>$slug );

return $this->db->insert('news', $data); }