Workbook is read only try again

Sub Wait15()
    Dim i As Long
    For i = 0 To 3
        If wBook.ReadOnly = True Then
            If i = 3 Then
                MsgBox "Database is in use. Please try again after some time.", vbOKOnly + vbCritical, "Error"
                Exit Sub
            End If
            Application.Wait Now + TimeValue("0:00:05")
        End If
    Next i
End Sub