Who is accessing file

I have seen examples of determining ownership of a file. Is there a way to determine who is accessing a file?

I have a program that needs to overwrite files. If one of these files is currently in use, I want to be able to inform the administrator that the file is currently being accessed and who is accessing the file.

If there is a way to do this with an API, that would be cool.

Thanks.

See richard dieckman post in this thread
http://forums.vb-world.net/showthrea...threadid=17376

I checked out the post but there is only a reference to this person having some information, not the actual information.

I tried emailing this person but the email address is no longer valid.

Any other ideas?