>In a multi-user program, what is the easiest way to tell if a table is opened by another user. I need to use the table from time to time exclusivly to do maintainance and will need to make sure all users are out of the table.

Here's an old but still good method, also:

nfilehandle = fopen('filename')
if nfilehandle >= 0
  =fclose(nfilehandle)  && it's available for you to open EXCL
else
 * it's in use
endif