Web services

Hi dear moodle-gurus:

I am recently trying to crate users using a SOAP call and a wsdl, but the thing is that I can't figure out how to create a new user with custom fields. If I create a new user without the custom fields it creates succesfully.

Here's what I've been doing:

<soapenv:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ser="http:XXXXXXXX/soap/server.php?wstoken=XXXXXX">

   <soapenv:Header/>

   <soapenv:Body>

      <ser:core_user_create_users soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">

         <users xsi:type="soapenc:Array" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/">

             <Item soapenc:id="id1">

               <username xsi:type="xsd:string">holauseron</username>

               <password xsi:type="xsd:string">Description_1.</password>

               <firstname xsi:type="xsd:string">Juan</firstname>

               <lastname xsi:type="xsd:string">Perez</lastname>

               <email xsi:type="xsd:string">johnycasszzh1@example.com</email>

               <auth xsi:type="xsd:string">manual</auth>

            </Item>

         </users>

      </ser:core_user_create_users>

   </soapenv:Body>

</soapenv:Envelope> 

This call is successful but if I do this: