Как вывести логин последнего зарегистрированного пользователя?

<?php
if(!defined('DATALIFEENGINE')) {
  	die("Hacking attempt!");
}

global $config;

$limit = $limit ? intval($limit) : "5";

if (!$r_regtop) {
$sql = $db->query("SELECT * FROM " . PREFIX . "_users ORDER BY reg_date DESC LIMIT 0,{$limit}");

while ($row = $db->get_row($sql)) { 
    $r_regtop.= "<div class=\"ratefull\" style=\"padding:0;text-align: center;\"><div style=\"width:35%;float: left;\"><a href=\"/user/{$row['name']}\">{$row['name']}</a></div><div style=\"width:35%;float: left;\"><a href=\"https://www.nic.ru/whois/?ip={$row['logged_ip']}\" target=\"_blank\">{$row['logged_ip']}</a></div> <span style=\"float: none;\"><a href=\"mailto:{$row['email']}\" target=\"_blank\">{$row['email']}</a></span></div>";
}

}
echo $r_regtop;
?>

{include file="engine/mods/regashort.php?limit=1"}

$lastName = $db->super_query("SELECT name FROM " . USERPREFIX . "_users ORDER BY reg_date DESC");
	echo $lastName['name'];