You can simply:

USE employee IN 0 AGAIN

and avoid the error message.

Or, intercept the error:

local llError
on error llError = .T.
use employee in 0
on error
if llError
  * There was a problem
endif

>Using VFP8, is there a way to tell if a table is in use if that table was opened with a different alias?
>
>For example:
>**************************
>USE employee IN 0 ALIAS emp &&This is OK.
>
>***However, later on in the application...
>IF !USED("employee") &&This will return TRUE.
> USE employee IN 0 &&This would result in a File In Use error.
>ENDIF
>SELECT employee &&This would also error.
>**************************
>
>I know this isn't the best practice but how could I tell if employee is already in use in the current data session?
>
>Thanks,
>
>Jerry