kantry, Оно?
// echo "/$onltime/" ;
$online_u = mysql_result(mysql_query("SELECT COUNT(*) FROM `users` WHERE `lastdate` > $onltime AND `place` = 'manager'"), 0);
$online_g = mysql_result(mysql_query("SELECT COUNT(*) FROM `cms_guests` WHERE `lastdate` > $onltime AND `place` LIKE 'manager%'"), 0);