PHP WSDL Hakkında Yardım

<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Header>
    <AuthenticationSoapHeader xmlns="http://example.com/WS">
      <WSUserName>WSusername</WSUserName>
      <WSPassword>WSpassword</WSPassword>
    </AuthenticationSoapHeader>
  </soap:Header>
  <soap:Body>
    <Ping xmlns="http://example.com/WS">
      <OTA_PingRQ>
        <EchoData>Ping data</EchoData>
      </OTA_PingRQ>
    </Ping>
  </soap:Body>
</soap:Envelope>

$client = new SoapClient("http://ws.example.com/WS.asmx?WSDL",array("trace"=>1));


$ns="http://example.com/WS";
$headerOptions=array("username"=>"admin","password"=>"123456");
$header = new SOAPHeader($ns, 'AuthenticationSoapHeader', $headerOptions);  
$client->__setSoapHeaders($header);

$pingOptions=array("EchoData"=>"asdasd");

$r=$client->Ping($pingOptions);
print_r($r);