Capture and store the approver id of an process flow user action in database

Hi
I am trying to capture the logged in user who approves/rejects a particular workunit in inbasket and then store it in custom table field within Lawson via an AGS call within Lawson.
Is there any way to capture the user id and store it into a variable while the user approves the workunit within processflow or do I need to check into some workunit history table to capture the same?

This is V10.