Permission Denied error 70 when using filecopy

I have a split database and wish to make a copy of the data back-end via code.  To do this, I have a button on a form which calls the copy routine.  One of the first actions in the code is to close the form which called the routine to ensure any remaining unwritten data is written to the database.

When I step through the code using F8 the routine works perfectly.  When I run the code from the button on the form, I get an Error 70 Permission Denied error on the FileCopy line.  I suspect that the backend database is still locked.  but I don't know how I can get around this problem.

I've tried putting in a loop that continues to try the filecopy routine until the Error 70 doesn't occur.  However, this doesn't seem to work as the routine gets trapped in the loop.

Is there a way to test if the Error 70 will occur before attempting it?  Maybe testing to see if the back-end database is still locked?

Here's the code:
=============
Sub CreateBackUp()
    On Error GoTo ErrTrap
   
    'close any open forms and present the backup dialog
    DoCmd.Close acForm, "frmContacts"
   
    'grab the current backend name to rename the copy when its made
    Dim myLinkedName
    myLinkedName = CurrentDb.TableDefs("tblContacts").Connect
    myLinkedName = Right(myLinkedName, Len(myLinkedName) - InStr(1, myLinkedName, "="))
   
    'make the copy
    FileCopy Source:=myLinkedName, destination:=Left(myLinkedName, Len(myLinkedName) - 6) & " " & Format(Now(), "yyyymmddhhss") & ".dcsdb"
   
    'reopen the contacts form
    DoCmd.OpenForm "frmContacts"
   
    'avoid the error trap
    Exit Sub
     
ErrTrap:
    MsgBox "An unexpected error occured and is described as: " & Err.Description
    DoCmd.OpenForm "frmContacts"
    Exit Sub
   
End Sub
=================

Many thanks for your help.