public function editKontrak($id = null)
 {
     if (Session::get('role') != 2) {
         $this->display();
         exit;
     }
     if ($id != "") {
         $kontrak = new Kontrak();
         $data = $kontrak->get_by_id($id);
         //var_dump($kontrak);
         $universitas = new Universitas($this->registry);
         $this->view->universitas = $universitas;
         $univ = $universitas->get_univ();
         $kon = $kontrak->get_All();
         $this->view->univ = $univ;
         $this->view->data = $data;
         $this->view->kon = $kon;
         $this->view->render('kontrak/edit_kontrak');
     } else {
         header('location:' . URL . 'kontrak/display');
     }
 }