public function UpdateUserCommentCounts($DiscussionID) {
      $Sql = "update ".$this->Database->DatabasePrefix."UserDiscussion ud
         set CountComments = (
            select count(c.CommentID)+1 
            from ".$this->Database->DatabasePrefix."Comment c 
            where c.DateInserted < ud.DateLastViewed
         )
         where DiscussionID = $DiscussionID";
      $this->SQL->Query($Sql);
   }