I have very little experience with Javascript.

I have a script which pops up a message that session time is about to run out and it is working like I want except for one thing. When the confirm message sets there without a response from the user I want to redirect them to sign on screen automically when the session time does run out. But instead as soon as an answer of continue it will reset the session time.

How can I automically redirect if the user does not reponse when the session does run out?