How to chatch "exit" button?

Hi all,
Please let me know how to catch the "exit" (x button in the top-right corner) so that I can ask whether or not user wants to quit.

Thank you.

In the form's query unload event:

if UnloadMode <> vbFormCode the
'Ask the user.
'if the user responds that he doesn't want to quit:
Cancel = true

end if

Write the folloing code on form unload event :


private Sub Form_Unload(Cancel as Integer)
Dim iChoice as Integer
iChoice = MsgBox("Are you sure ? ", vbYesNo, "Exit")
If iChoice = vbNo then
Cancel = true
End If
End Sub