so, if I understand you right, say a user clicks a particular button or link, you want to make sure nothing alfter that point works? Or he is automatically redirected to a particular site no matter what he clicks after some event?
I would solve this in ASP, set a session level variable following the event, then any page he lands on, redirect or handle the variable. It might be easier to send him to a dead-end if the event occurs.
Now that I mention it, it might be easier to not do this at all. Why are you trying to do this in the first place?