prevent any modifications at Purchase Requistion Item

Hi Experts,

I have the hint of you to use the Badi ME_PROCESS_REQ_CUST for my request.

However, I have researched slightly and do not know how to implement this Badi especially for my case.

Which method should I take here actually to lock an item of Purchase Requisition ?

Not allowing to make a change at some Purch. Req.

Has someone an example of me.

Any help on this would be highly appreciated.

Kindly Regards

Erdem Sas