XML : How to add pagination to php sitemap?

I have sitemap by yoast. It's a standalone sitemap for static files. What I was trying to to for a last few days was to add pagination and I failed. Maybe anyone could help me to add pagination? Here is code:

  <?php    /**   * XML Sitemap PHP Script   * For more info, see: http://yoast.com/xml-sitemap-php-script/   * Copyright (C), 2011 - 2012 - Joost de Valk, joost@yoast.com   */    require './config.php';    // Get the keys so we can check quickly  $replace_files = array_keys( $replace );    // Sent the correct header so browsers display properly, with or without XSL.  header( 'Content-Type: application/xml' );    echo '<?xml version="1.0" encoding="utf-8"?>' . "\n";    $ignore = array_merge( $ignore, array( '.', '..', 'config.php', 'xml-sitemap.php' ) );    if ( isset( $xsl ) && !empty( $xsl ) )      echo '<?xml-stylesheet type="text/xsl" href="' . SITEMAP_DIR_URL . $xsl . '"?>' . "\n";    function parse_dir( $dir, $url ) {      global $ignore, $filetypes, $replace, $chfreq, $prio;        $handle = opendir( $dir );      while ( false !== ( $file = readdir( $handle ) ) ) {            // Check if this file needs to be ignored, if so, skip it.          if ( in_array( utf8_encode( $file ), $ignore ) )              continue;            if ( is_dir( $file ) ) {              if ( defined( 'RECURSIVE' ) && RECURSIVE )                  parse_dir( $file, $url . $file . '/' );          }            // Check whether the file has on of the extensions allowed for this XML sitemap          $fileinfo = pathinfo( $dir . $file );          if ( in_array( $fileinfo['extension'], $filetypes ) ) {                // Create a W3C valid date for use in the XML sitemap based on the file modification time              if (filemtime( $dir .'/'. $file )==FALSE) {                  $mod = date( 'c', filectime( $dir . $file ) );              } else {                  $mod = date( 'c', filemtime( $dir . '/' . $file ) );              }                // Replace the file with it's replacement from the settings, if needed.              if ( in_array( $file, $replace ) )                  $file = $replace[$file];                // Start creating the output      ?>        <url>          <loc><?php echo $url . rawurlencode( $file ); ?></loc>          <lastmod><?php echo $mod; ?></lastmod>          <changefreq><?php echo $chfreq; ?></changefreq>          <priority><?php echo $prio; ?></priority>      </url><?php          }      }      closedir( $handle );  }    ?>  <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><?php      parse_dir( SITEMAP_DIR, SITEMAP_DIR_URL );  ?>    </urlset>