No changes aloowed in transaction

Dear Folks,

I have configured 18 statuses for my transaction. Out of that 3 statuses I have assigned business transaction "FINI". e.g. I assigned FINI to 3,6,18th no. status.

At 3,6 and 18 status I get system and user status as "completed" but system allows changes in transaction on 3rd and 6th status even if it is considered to be completed. But on 18th status system doesnt allow any changes in transaction.

I want no changes to be made on status 3rd and 6th too. How can I do that?

Regards,

Nikhil