Able to attach documents when the document in closed status

Hi,

I have a issue related to attchments in Service Request.

I have user status =closed ands set Chnage Document=Forbidden for that staus.

Now after setting this Status, system is not allowing me to do any chnages in the document and that is fine.

But system still allows to add the attchments and I want to stop it if the status is closed.

What I need to do.

Regards

babu.