Workflow ?

Hello DUG experts..

Here i want to ask you something about workflow..Actually Nav2106 have already most useful workflow templates to fulfill Business requirement.."General Journal Line Approval Workflow" is one of them..So question is,that in PI/PO approval,there is a field in Purchase Header name STATUS changed OPEN to Pending Approval..But there is no STATUS field in General Journal Line and i want same functionality on GJL when an approval request is made by user.

I added a field name STATUS of option type..But i didnt find that how workflow management processing is done,i tried it to understand with debugger,also but it difficult to understand..Can any one help me out,how can i do this?

I want to do it as standard functionality.

Kind regards ..