In MDI applications, a user might have two or three or even more MDI child windows open at any given time. But in applications where you have user log-in and log-out security, you likely want to unload all open forms when the user logs out. To accomplish this, use this small piece of code:
Do Until MDIform1.ActiveForm Is Nothing
If you need to save any values in any form by default, you can include a call to the appropriate Save method in the Unload event of that form.