PHP操作xml

/*获取图片新闻列表*/
function getPicNews($number=5){
require_once 'include/content_class.php';
$Content=new Content();
$sql='select contentid as id,title,pic,typeid from `cms_content` where pic<>"" order by input_time desc';
$rows=$Content->getRowsBySQL($sql,$number);
$dom=new DOMDocument('1.0','GBK');
$root=$dom->createElement('slider');
$dom->appendChild($root);
foreach($rows as $val){
$item=$dom->createElement('item');
$root->appendChild($item);

$title=$dom->createAttribute('title');
$title_text=$dom->createTextNode($val['title']);
$title->appendChild($title_text);
$item->appendChild($title);

$href=$dom->createAttribute('href');
$href_text=$dom->createTextNode('show.php?newsid='.$val['id'].'&classid='.$val['typeid']);
$href->appendChild($href_text);
$item->appendChild($href);

$imageurl=$dom->createAttribute('imageurl');
$imageurl_text=$dom->createTextNode($val['pic']);
$imageurl->appendChild($imageurl_text);
$item->appendChild($imageurl);
}
return $dom->saveXML();
}