$users = mysql_result(mysql_query("SELECT COUNT(*) FROM `users` WHERE `lastdate` > '" . (time() - 300) . "'"), 0); 

$guests = mysql_result(mysql_query("SELECT COUNT(*) FROM `cms_sessions` WHERE `lastdate` > '" . (time() - 300) . "'"), 0); 

$total = $users + $guests;

echo '<div class="menu">Hozir saytda: ' .$total. '<br/>Foydalanuvchilar: ' .$users. '<br/>Mehmonlar: ' .$guests. '</div>';