Do Something When MsgBox Is Closed

I'm making a program in NS BASIC/CE that shows the user a warning, but when the user closes the MsgBox(clicking in OK), I want that the application executes AfterWarn Sub. H开发者_运维问答ow I can do this?

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Sorry, I read a little wrong But her:

Dim varResponse As VbMsgBoxResult
vResult = Msgbox("Are you sure you wanted to make this change?.",vbOkCancel)
If result = vbOk Then
    AfterWarn()
Else
   'Do something else?
End if