Mine

function sitemap_loop($array, $level) {
	global $domain; global $xml;
	foreach($array as $key => $item) {
		if(is_array($item) && !isset($item['link'])) {
			sitemap_loop($item, $level + 1);
		}
		else {
			$xml .= '<url>'."\n";
			$xml .= "  ".'<loc>'.$domain.$item['link'].'</loc>'."\n";
			$xml .= "  ".'<lastmod>'.$item['lastmod'].'</lastmod>'."\n";
			$xml .= '</url>'."\n";
		}
	}
}

$xml = '';
sitemap_loop($sitemap_array,0);