Wie verarbeite ich diese XML Struktur mit PHP5 ?

<?php

	error_reporting(E_ALL|E_STRICT);
	ini_set('display_errors','On');  

	$data = <<<'XML'  
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>  
<ns4:result xmlns="http://services1.domain.de/schema/resource" xmlns:ns2="http://services1.domain.de/schema/ad" xmlns:ns3="http://services1.domain.de/schema/seller" xmlns:ns4="http://services1.domain.de/schema/search" max-pages="1" current-page="1" page-size="20" total="2">  
<ns3:seller url="http://services1.domain.de/1.0.0/seller/123456" key="123456">  
    <ns3:type commercial="true" value="DEALER"/>  
    <ns3:company-name value="DEALER NAME"/>  
    <ns3:address>
          <ns3:street value="Strasse 10"/>  
          <ns3:zipcode value="80000"/>  
          <ns3:city value="München"/>  
          <ns3:country-code value="DE"/>  
     </ns3:address>
     <ns3:phone number="123456" area-code="089" country-calling-code="49" type="FIXED"/>  
     <ns3:phone number="123456" area-code="089" country-calling-code="49" type="FAX"/>  
     <ns3:email value="email@domain.de"/>  
     <ns3:homepage value="http://home1.domain.de/DEALERNAME"/>  
     <ns3:USER-seller-since value="1998-10-06+02:00"/>  
</ns3:seller>
</ns4:result>
XML;

	$obj = simplexml_load_string($data,'SimpleXMLElement');  

	
	$ns3 = $obj->children('http://services1.domain.de/schema/seller');  
	
	var_dump($ns3->seller->address->street->attributes());

?>