/**
  * @see parent::store()
  */
 function store()
 {
     $this->completeField("datetime_start");
     if (!$this->datetime_start) {
         $this->datetime_start = CMbDT::dateTime();
     }
     if (!$this->_id) {
         $rand = CMbSecurity::getRandomString(16);
         $this->hash = CMbSecurity::hash(CMbSecurity::SHA1, $rand);
     }
     return parent::store();
 }