Status 'closed' to be final status?

[bshterev]

Hallo, everyone,
I searched the forum, but no success, so I will post my question here, hope to help me!
I want the status 'closed' on my bugs to be final, e.g. to be impossible from 'closed' to to any other status!
I could nod achieve this from the web interface (in section "Workflow Transitions" ), because the changes I made did not take effect - always remain the option from 'closed' to go to 'reopen' status and I want to prohibit this!
I use version on Mantis 1.0.6.
Any help would be appreciated!
Thanks