public function check_validity_to_post_status($ans_id, $u_id)
 {
     $valid_status = Answers_status::where('user_id', $u_id)->where('answer_id', $ans_id)->get()->toArray();
     if (count($valid_status) > 0) {
         return TRUE;
     } else {
         return FALSE;
     }
 }