get property from XML using PHP

I am using PHP's SimpleXML to get some values out of the following XML;

- <entry>
  <id>http://www.google.com/m8/feeds/contacts/email_address%40gmail.com/base/0</id> 
  <updated>2010-01-14T22:06:26.565Z</updated> 
  <开发者_Go百科category scheme="http://schemas.google.com/g/2005#kind" term="http://schemas.google.com/contact/2008#contact" /> 
  <title type="text">Customer Name</title> 
  <link rel="http://schemas.google.com/contacts/2008/rel#edit-photo" type="image/*" href="http://www.google.com/m8/feeds/photos/media/email_address%40gmail.com/0/34h5jh34j5kj3444" /> 
  <link rel="self" type="application/atom+xml" href="http://www.google.com/m8/feeds/contacts/email_address%40gmail.com/full/0" /> 
  <link rel="edit" type="application/atom+xml" href="http://www.google.com/m8/feeds/contacts/email_address%40gmail.com/full/0/5555" /> 
  <gd:email rel="http://schemas.google.com/g/2005#other" address="customer@gmail.com" primary="true" /> 
  </entry>

I can get the title with:

$xml = new SimpleXMLElement($response_h1);

foreach ($xml->entry as $entry) {
   echo $entry->title, '<br />';
}

But how to get the address="customer@gmail.com" property?

Your namespace is invalid. If no namespace, you should be able to fetch the address like this,

$email = (string)$xml->email['address'];

There are some bugs in SimpleXML. The elements work with member syntax "->" but the attributes are only accessible using array syntax "[]".