How do I make sure a certain worksheet is completed properly before
closing Excel?

I have this code that I obtained from various postings in this
newsgroup on each worksheet:
-------

Private Sub Worksheet_Deactivate()
Const rngWeek As String = "nrmWWeek"
Const rngTotal As String = "gTotal"
Const rngLast As String = "lastDay"

prevSheet = Me.Name

On Error GoTo stoppit
Application.EnableEvents = False

If Me.Range(rngLast).Value < 0 Then
If Me.Range(rngTotal).Value < Me.Range(rngWeek).Value Then
Response = MsgBox("Please return to the T&T worksheet
and make corrections", _
vbOKOnly, "Total Hours Error")
Worksheets(prevSheet).Select
End If
End If

stoppit:
Application.EnableEvents = True

End Sub

--------

It checks if whether the value in nrmWWeek match the value in gTotal
and if it doesn't the user is prompted to make a corrections and
activates the previous active worksheet (prevSheet is Global). It
only works when the worksheet is deactivated. However, I also want to
prevent them from closing the workbook before making the corrections.
I know I need to insert 'some' code in the "ThisWorkbook" using
Workbook_BeforeClose but I have no idea how.

I attempted to modify the above and inserted it in the BeforeClose
event but failed. The code


Thank you,