PHP soap call results from a function

I have an wsdl file with a function that returns results

<s:element name="RecordDataResponse">
<s:complexType>
<s:sequence>
<s:element minOccurs="0" maxOccurs="1" name="RecordDataResult" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="message" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>

I tried this but came up with an invalid function result.. i just want to get the value from this function

$response2 = $soapclient->RecordDataResponse()->RecordDataResult;

but get this error

Uncaught SoapFault exception: [Client] Function ("RecordDataResponse") is not a valid method for this service in ...

any hints? using windows php and I can put data in ..