lock up a stack

[Sannyasin Sivakatirswami]

I want to be able to "lock up" a stack such that the user cannot select 
text in fields, but all the buttons run.. then, when he clicks "edit" 
the application drops a "in use" semaphore file on the server so that 
others can read the stack from the server but not make changes... and 
the user with edit privileges can now edit text and when he saves, the 
changes are saved to a temp stack on disk and the app FTP's the changed 
stack back to the server and delete the semaphore file.

Goal: A kind of lame duck multi-user context with RCS where the number 
of users is very small <10 and usage will be intermittent. Their may be 
better ways to do this, but a single stack is "so sweet" and easy to 
manage.  What is wanted is a kind of global lock text function that 
does not require scripts to run through all fields in the mains stack 
and substacks. but simply lock all the text in one go...

Ideas?

Sivakatirswami