How do I read SOAP reply Envelope by PHP

Question

How do I read the error_code from this SOAP reply Envelope? My PHP version is: 5.2.0.

<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope">
 <soap:Body>
  <Response xmlns="http://xxx.gateway.xxx.abcd.com">
   <return>
      <transaction_id>1234567</transaction_id>
      <error_code>109</error_code>    
   </return>
  </Response>
 </soap:Body>
</soap:Envelope>

I just need to read the value of error_code tag.here the value is :109

I am using nusoap. I used the below code but not working properly:

$response=htmlspecialchars($client->response, ENT_QUOTES);
$xml = simplexml_load_string($response); 
$ns = $xml->getNamespaces(true); 
$soap = $xml->children($ns['soap']); 
$error_code = $soap->body->children($ns['error_code']);

Answer 1

<?php 

$string = <<<XML
<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope">
 <soap:Body>
  <Response xmlns="http://xxx.gateway.xxx.abcd.com">
   <return>
      <transaction_id>1234567</transaction_id>
      <error_code>109</error_code>    
   </return>
  </Response>
 </soap:Body>
</soap:Envelope>
XML;

$xml = new SimpleXMLElement($string); 
$xml->registerXPathNamespace("soap", "http://www.w3.org/2003/05/soap-envelope");
$body = $xml->xpath("//soap:Body");
$error_code = (string)$body[0]->Response->return->error_code;
print_r($error_code); 
?> 

OR

 $xml = simplexml_load_string($string); 
 $error_code = (string)$xml->children('soap', true)
                            ->Body
                            ->children()
                            ->Response
                            ->return
                            ->error_code;