You should be able to get away without APIs.
Open the workbook Read only, then check the WriteReservedBy property of the
workbook.


With ActiveWorkbook
If .WriteReserved = True Then
MsgBox "Opened by " & .WriteReservedBy
End If
End With


--

HTH

RP
(remove nothere from the email address if mailing direct)


"Paul Martin" wrote in message
ups.com...
Hi

I am writing code to open another Excel file. If the file is in use by
another user, I would like to use an API function to return the network
username of the person who has the file open. Any suggestions?

Thanks in advance

Paul Martin Melbourne, Australia