$autoupdate = mysql_query("
		UPDATE booklogs SET
		remain = IF(TIMESTAMPDIFF(HOUR,reservetime,NOW()) >=24 , NULL , TIMEDIFF('24:00:00', TIMEDIFF(NOW(),reservetime)) ) ,
		status = IF(TIMESTAMPDIFF(HOUR,reservetime,NOW()) >=24 , 'c' , 'r' ) ,
		canceltime = IF(TIMESTAMPDIFF(HOUR,reservetime,NOW()) >=24 , NOW() , NULL ) ,
		archive = IF(TIMESTAMPDIFF(HOUR,reservetime,NOW()) >=24 , '1' , '0' ) ,
		canceluser = IF(TIMESTAMPDIFF(HOUR,reservetime,NOW()) >=24 , 'reservation_expired' , NULL )
		WHERE status='r'
		AND archive=0
	
	");