Binding Task container to Method container

[Swam_in]

Hello,
 
I am trying to get the task container variable _Woritem to the method source
code. I declared the method container element same as workingwi ( or same as
_workitem ). The binding between method and task looks good. All I am trying
to do is getting the task container elements 'Created by user' & 'Actual
work item agent' over to method.
Any idea how do I make use of system container elements ?
Appreciating any suggestions.
 
Swami