/**
  * Manages all models.
  */
 public function actionIndex()
 {
     if (!isset($_SESSION['course_id'])) {
         $course = Course::model()->find();
         $_SESSION['course_id'] = (int) $course->ID;
     }
     if (isset($_GET['ID'])) {
         $_SESSION['course_id'] = $_GET['ID'];
     }
     $model = new Classmanager('search');
     $model->unsetAttributes();
     // clear any default values
     $model->ID_course = $_SESSION['course_id'];
     if (isset($_GET['Classmanager'])) {
         $model->attributes = $_GET['Classmanager'];
     }
     $this->render('admin', array('model' => $model));
 }