XML Parsing

Hi,

I have file people.wsdl:

<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions 
targetNamespace="http://localhost:8080/wsapp/services/PeopleService" 
xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/">
   <wsdl:portType name="PeopleService">
     <wsdl:operation name="add" parameterOrder="name sex age"/>
     <wsdl:operation name="getList"/>
     <wsdl:operation name="del" parameterOrder="id"/>
   </wsdl:portType>
</wsdl:definitions>

I need to get all wsdl:portType and all wsdl:operation for every 
wsdl:portType.

Code:

var doc = 
document.implementation.createDocument("http://schemas.xmlsoap.org/wsdl/","wsdl",null);
doc.load("people.wsdl");
var definitions = doc.getElementsByTagName("definitions");
alert(definitions[0].getAttribute("targetNamespace"));
var portType = doc.getElementsByTagName("portType");
alert(portType[0].getAttribute("name"));
var operation = doc.getElementsByTagName("operation");
for(var i=0; i<portType.length; i++) {
    alert(operation[i].getAttribute("name"));
}

On line 4 I got error:

Error: definitions[0] has no properties

What's wrong?

Can I use XPath expressions like this:

getElementsByTagName("/definitions/portType/operation[0]") ?

--
Thanks,
Eugene Prokopiev