xml parsing error, using php's asxml

[pano pano]

$file = simplexml_load_file($url); {
 
 
    foreach($file->entry as $post) {
 
 
    $row = simplexml_load_string($post->asXML()); // after adding this line, i get error message
 
    $links = $row->xpath('//link[@rel="alternate" and @type="text/html"]');
    echo (string) $post->title;
    echo (string) $links[0]['href'];

I use this script to parse atom feed. At first didn't work because it couldn't pass the link's href attribute properly. I added $row and even though it worked, it gives an error : "namespace prefix gd for etag on entry is not defined". I'm searching this for hours, can't find a solution. Can anyone help please?

[Dormilich]

then you haven’t searched properly. it is known that SimpleXML doesn’t use Namespaces by default and how to incorporate them is an easy search.