Need help with creating a sitemap for coppermine gallery

HI I found a plugin which I installed into my coppermine gallery which creates a google sitemap for it, but it's saved as .php file. There's instructions on how to convert it into an xml file, but I haven't been able to do it right. Maybe you guys can help me out. Here is the instructions and code:

<?php

/*
Google sitemap generator for PHP4.1+ and CPG 1.2+
*/

// use time of last comment on a pic as lastmod ? (if false then we just use pic's upload time (ie. db, not EXIF) which is cheaper)
define('INC_COMMENT_TIMES', false);

// dump the sitemap to a specified file (or generally anything accessible via fopen()), or false to output straight to user agent.
// Be aware that if you enable this and the output buffer exceeds php's memory limit and ini_set() fails the script will crash and burn.
// Use a .gz or .xml.gz ending if you are making a compressed file.
//define('FILEDUMP', 'sitemap.xml');
define('FILEDUMP', false);

// use gzip compression ? disable if you have zlib output compression enabled
// Zlib support in PHP is not enabled by default. You will need to configure PHP --with-zlib[=DIR]
// The windows version of PHP has built in support for this extension. You do not need to load any additional extension in order to use these functions.
// Note: Builtin support for zlib on Windows is available with PHP 4.3.0.
define('GZ_COMPRESS', false);

// [0.0 <= priority <= 1.0]
define('P_DISPLAYIMAGE', 0.5);
define('P_ALBUM', 0.5);
define('P_CATEGORY', 0.5);

// [changefreq = always || hourly || daily || weekly || monthly || yearly || never]
define('CF_DISPLAYIMAGE', 'unspecified');
define('CF_ALBUM', 'unspecified');
define('CF_CATEGORY', 'unspecified');

define('IN_COPPERMINE', true);
require('include/init.inc.php');

// This should work as it is, but hardcode if necessary.
define('CPG14', version_compare(COPPERMINE_VERSION, "1.4.0", ">="));
define('PHP5', version_compare(phpversion(), "5", ">="));

// No user servicable parts below here

function lmdate($timestamp)
{
if (PHP5){
return date('c', $timestamp);
} else {
return date('Y-m-d\TH:i:s+00:00', $timestamp - date('Z'));
}
}

$base = rtrim($CONFIG['ecards_more_pic_target'], '/');

if (FILEDUMP){
@ini_set('memory_limit', '32M');
ob_start();
} else {
header('Content-type: text/xml');
}

if (GZ_COMPRESS){
@ini_set('memory_limit', '32M');
if (!FILEDUMP) ob_start("ob_gzhandler");
}

echo '<?xml version="1.0" encoding="UTF-8"?>';
echo '<urlset xmlns="http://www.google.com/schemas/sitemap/0.84">';

$cats = mysql_query("SELECT cid FROM {$CONFIG['TABLE_CATEGORIES']}");

$pass = CPG14 ? "AND (ISNULL(alb_password) OR alb_password = '')" : '';

echo '<url>';
echo "<loc>$base</loc>";
echo "<priority>1.0</priority>";
echo '</url>';

while(list($cid) = mysql_fetch_row($cats))
{
echo '<url>';
echo "<loc>$base/index.php?cat=$cid</loc>";
if (CF_CATEGORY != 'unspecified') echo '<changefreq>'.CF_CATEGORY.'</changefreq>';
if (P_CATEGORY != '0.5') echo '<priority>'.P_CATEGORY.'</priority>';
echo '</url>';

$albs = mysql_query("SELECT a.aid, MAX(ctime) FROM {$CONFIG['TABLE_ALBUMS']} AS a INNER JOIN {$CONFIG['TABLE_PICTURES']} AS p ON p.aid = a.aid WHERE category = '$cid' OR category > ".FIRST_USER_CAT." AND visibility = 0 $pass GROUP BY a.aid");

while(list($aid, $lastmod) = mysql_fetch_row($albs))
{
echo '<url>';
echo "<loc>$base/thumbnails.php?album=$aid</loc>";
echo '<lastmod>'.lmdate($lastmod).'</lastmod>';
if (CF_ALBUM != 'unspecified') echo '<changefreq>'.CF_ALBUM.'</changefreq>';
if (P_ALBUM != '0.5') echo '<priority>'.P_ALBUM.'</priority>';
echo '</url>';

$pics = mysql_query("SELECT pid, ctime FROM {$CONFIG['TABLE_ALBUMS']} AS a INNER JOIN {$CONFIG['TABLE_PICTURES']} AS p ON p.aid = a.aid WHERE p.aid = '$aid'");

while(list($pid, $lastmod) = mysql_fetch_row($pics))
{
if (INC_COMMENT_TIMES){
$com = mysql_query("SELECT UNIX_TIMESTAMP(MAX(msg_date)) FROM {$CONFIG['TABLE_COMMENTS']} AS c INNER JOIN {$CONFIG['TABLE_PICTURES']} AS p ON p.pid = c.pid WHERE p.pid = '$pid' GROUP BY p.pid");
if (mysql_num_rows($com)) list($lastmod) = mysql_fetch_row($com);
mysql_free_result($com);
}
echo '<url>';
echo "<loc>$base/displayimage.php?pos=-$pid</loc>";
echo '<lastmod>'.lmdate($lastmod).'</lastmod>';
if (CF_DISPLAYIMAGE != 'unspecified') echo '<changefreq>'.CF_DISPLAYIMAGE.'</changefreq>';
if (P_DISPLAYIMAGE != '0.5') echo '<priority>'.P_DISPLAYIMAGE.'</priority>';
echo '</url>';
}
}
}
echo '</urlset>';

if (FILEDUMP){
if (GZ_COMPRESS){
if ($zp = gzopen(FILEDUMP, "w9")){
gzwrite($zp, ob_get_contents());
ob_end_clean();
gzclose($zp);
die('Completed, compressed and dumped to ' . FILEDUMP);
} else {
die('Failed to create compressed output file [' . FILEDUMP . '] check dir permissions and verify gzip capability');
}
} else {
if ($fp = fopen(FILEDUMP, 'w')){
fwrite($fp, ob_get_contents(), ob_get_length());
ob_end_clean();
fclose($fp);
die('Completed, and dumped to ' . FILEDUMP);
} else {
die('Failed to create output file [' . FILEDUMP . '] check dir permissions or create and chmod the file for me');
}
}
}
if (GZ_COMPRESS) ob_end_flush();

What I want to know is what the code should look like if I'm changing a certain part or parts to define('FILEDUMP', 'sitemap.xml') ?