function delete($id)
{
$topic = new Topic($id);
$question = new Questionaire();
$answer = new Answer();
$answer->where_related('questionaire', 'topic_id', $id)->get()->delete_all();
$choice = new Choice();
$choice->where_related('questionaire', 'topic_id', $id)->get()->delete_all();
$question->where('topic_id', $id)->get()->delete_all();
$topic->delete();
set_notify('success', 'ลบข้อมูลเรียบร้อยแล้วค่ะ');
redirect($_SERVER['HTTP_REFERER']);
}
