[flexcoders] Omitting a webservice input parameter

[Viju James]

I want to call a webservice through Flex (2.0.1 HotFix3) without 
passing one of the parameters. I can do this using other tools like 
Altova XMLSpy and it works fine. But, Flex complains saying "Required 
parameter 'attributeNames' not found in input arguments."
If I add <attributeNames></attributeNames>, then Flex is happy, but 
the web service doesn't return anything since it will return all 
attributeNames only if that parameter is not passed when it is 
called. Is there a way to do this (i.e., to not pass this) in Flex?

Here is the operation that I use in Flex.

<mx:operation name="GetAttributes">
        <mx:request>
                <loginInfo>
                        <userId>Demo</userId>
                </loginInfo>
                <classNameId>
                        <namespaceName>CORE</namespaceName>
                        <className>ComputerSystem</className>
                </classNameId>
                <attributeNames></attributeNames>
        </mx:request>
</mx:operation>

Basically, I want to omit <attributeNames> in the request.

here is the xml request that I send through Altova XMLSpy and there 
it works fine.

<SOAP-ENV:Body>
        <m:GetAttributes xmlns:m="http://abc.mycompany.com";>
                <loginInfo>
                        <userId>Demo</userId>
                </loginInfo>
                <classNameId>
                        <namespaceName>CORE</namespaceName>
                        <className>ComputerSystem</className>
                </classNameId>
        </m:GetAttributes>
</SOAP-ENV:Body>