Another way is to include a meta refresh tag in the <head> section of your page like this:
<head>
<meta http-equiv="refresh" content="600">
</head>
The content part is the number of seconds before the page is reloaded, 10 minutes in this example (600 seconds).
The only problem is that if the user begins a form entry and hasn't submitted by the refresh time, the page will reload and any form entries will be lost.
Set the refresh time to be a little less than your ASP session timeout time to guarantee that the page reloads and the session stays active.