Attribute names sent from soapUi

I have created a web service with Yii and am testing it with soapUi as the client. My main problem is to figure out how to pass the attribute names of each field. I get the values and I can work with them as long as the order of them is exactly how I want it. But is there any way to control attribute names in arrays? Example: I want the tag "id" within datalist to be passed to the controller. It works for the Strings defined, but not for tags in the array. Can anyone point me in the right direction?

Below you can see the client call:

And the method retrieving it is like this: