reseting cookie_lifetime

I have: session.cookie_lifetime = 1200 in my php.ini. I am using the PHP session functions that are working fine, except I can't find out how to reset the lifetime timer. For example, I log in, my script creates the session, and I do my work. After 20 minutes of working, the session expires and I have to re-login. How can I reset the cookie_lifetime timer so that after each request the 20 minute lifetime starts over? Each script starts with: session_name("mysessionname"); session_start(); And then checks session_is_registered('username') Thanks, Justin England jengland@enetis.net Network Administrator E-Net Information Services http://www.enetis.net Tel: 605-341-3638 Fax: 605-341-8880