/**
  * The getZoneBannerStatistics method returns banner statistics for a zone
  * for a specified period.
  *
  * @access public
  *
  * @param string $sessionId
  * @param integer $zoneId
  * @param date $oStartDate
  * @param date $oEndDate
  * @param recordSet &$rsStatisticsData  return data
  *
  * @return boolean
  */
 function getZoneBannerStatistics($sessionId, $zoneId, $oStartDate, $oEndDate, &$rsStatisticsData)
 {
     if ($this->verifySession($sessionId)) {
         return $this->_validateResult($this->_dllZone->getZoneBannerStatistics($zoneId, $oStartDate, $oEndDate, false, $rsStatisticsData));
     } else {
         return false;
     }
 }