Using DW8 .asp web page

I want to redirect the user to the home page when no activity has been performed in 10 minutes (data is very sensitive).

The welcome page is in an iframe and displays data based on which button selected.

All data is coming from sql server (unlimited timeout).

If the screen sits long enough all data will disappear and I'm left with just a web page.

Do I have to add code to each page? If so what?