Preventing PopUp Ads

Using VB 5 Pro

Is there a way to prevent popup ads?
I know the documentComplete is fired for every document.
I also know I can stop new pages from loading in the NewWindow2.
But how can I prevent a new window if the user didn't click something
to cause it.

Also is it possible to allow new windows if the user clicked a link
that opens in a new window but not allow one the just does it without
the user.