Block record from being viewed by other users. Access 2000

I have a flat-file front-end back-end access 2000 database that is used by 4 to 5 people simultaneously on a network. Each user uses a separate .mde file to enter data. The problem is that periodically record corruption occurs in the memo field of the form when two users are accessing the same record at the same time. I have fought this problem in different ways to no avail.
What I would like to do is somehow filter out any record that is currently being viewed by a user so that all others would be unable to access it and thus (hopefully) avoiding the aforementioned corruption problem. Does anyone have any ideas?

Thanks

On a flat file? Not possible?
I dont recall Access having a flag for record edited. It usually locks space on either side - you could try and look for that.

Alternatively, hold the editting record unique ID in a table against a user, then then they have to release it before another user can edit that record.

Various other methods, but you've probably tried most.