At this point you have a fully functioning SOAP Server. Clients can connect to it and request data. If you haven't done so already, bring up the script in your browser and see what you get. You should get a page giving you a link to the WSDL document for the Server. Click on it and you should see the resulting WSDL document. Surprise, surprise, it is in XML! If you read over this document, you will see that it describes what happens for a request and as a response for your particular SOAP Service.
Note that while it is possible to create a SOAP Server without having it create the WSDL file, I recommend creating the WSDL document anyway. It is simple enough, so why not?