I want to change encoding this script to tis-620 please introduce to me



include 'mainfile.php';
include_once XOOPS_ROOT_PATH.'/class/template.php';
include_once XOOPS_ROOT_PATH.'/modules/news/class/class.newsstory.php';
if (function_exists('mb_http_output')) {
mb_http_output('pass');
}
header ('Content-Type:text/xml; charset=utf-8');
$tpl = new XoopsTpl();
$tpl->xoops_setCaching(2);
$tpl->xoops_setCacheTime(3600);
if (!$tpl->is_cached('db:system_rss.html')) {
$sarray = NewsStory::getAllPublished(10, 0);
if (is_array($sarray)) {
$tpl->assign('channel_title', xoops_utf8_encode(htmlspecialchars($xoopsConfig['sitename'], ENT_QUOTES)));
$tpl->assign('channel_link', XOOPS_URL.'/');
$tpl->assign('channel_desc', xoops_utf8_encode(htmlspecialchars($xoopsConfig['slogan'], ENT_QUOTES)));
$tpl->assign('channel_lastbuild', formatTimestamp(time(), 'rss'));
$tpl->assign('channel_webmaster', $xoopsConfig['adminmail']);
$tpl->assign('channel_editor', $xoopsConfig['adminmail']);
$tpl->assign('channel_category', 'News');
$tpl->assign('channel_generator', 'XOOPS');
$tpl->assign('channel_language', _LANGCODE);
$tpl->assign('image_url', XOOPS_URL.'/images/logo.gif');
$dimention = getimagesize(XOOPS_ROOT_PATH.'/images/logo.gif');
if (empty($dimention[0])) {
$width = 88;
} else {
$width = ($dimention[0] > 144) ? 144 : $dimention[0];
}
if (empty($dimention[1])) {
$height = 31;
} else {
$height = ($dimention[1] > 400) ? 400 : $dimention[1];
}
$tpl->assign('image_width', $width);
$tpl->assign('image_height', $height);
$count = $sarray;
foreach ($sarray as $story) {
$tpl->append('items', array('title' => xoops_utf8_encode(htmlspecialchars($story->title(), ENT_QUOTES)), 'link' => XOOPS_URL.'/modules/news/article.php?storyid='.$story->storyid(), 'guid' => XOOPS_URL.'/modules/news/article.php?storyid='.$story->storyid(), 'pubdate' => formatTimestamp($story->published(), 'rss'), 'description' => xoops_utf8_encode(htmlspecialchars($story->hometext(), ENT_QUOTES))));
}
}
}
$tpl->display('db:system_rss.html');
?>


Thank you very much