Determining why  Form_Unload is triggered

I have a form running in Access 2003. It has an Exit button with this code
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Private Sub btnExit_Click()
'----------------------------------------
   MsgBox "Data uploaded.  Thank you!", vbExclamation, "Attention !"
   Me.Visible = False
'----------------------------------------
'    loGQuittingFromApplication is declared in Global module as a boolean.
'    loGQuittingFromApplicationset is false at form load
'----------------------------------------
   loGQuittingFromApplication = True     'means I'm leaving correctly
   DoCmd.Quit acQuitSaveAll              loGQuittingFromApplication
End Sub
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In Form_Unload I look at loGQuittingFromApplication to see if I'm leaving from the Exit button or the "X", which I want to intercept.
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Private Sub Form_Unload(Cancel As Integer)
'Run your "proprer form entry" code here.
   Dim vbButtonsToShow As VbMsgBoxStyle
   vbButtonsToShow = vbYesNo
   If loGQuittingFromApplication Then
      'ok to quit
   Else
      If MsgBox("Do you really wish to quit ?", vbButtonsToShow, "Confirmation Required !") = vbYes Then
           G_UpdateLogInOut strGUserID, "Qt"
           Cancel = False
      Else
           Cancel = True
      End If
   End If
End Sub
=========================================================
I find that this works fine to intercept the user when they try to leave using the "X" on the title bar of Access, but if this handler is called as a result of the Exit button causing the application to exit I find that the variable loGQuittingFromApplication has been reset to False. I find the same with a public variable declared within the form (not application-global).

Is there a reason why these variables are being reset ? Is there a "standard" way of communicating the difference between a "DoCmd.Quit " and use of the "X" button to Form_Unload() ? Start Free Trial