Need the option in IIS where i can modify to extend the time for a session timeout for users for a website

Hi Experts,

I have a website hosted in my Windows Server 2008 r2. The website logs of users in a short time and they have to re sign it to the website again and again. I need the option where i can alter this in IIS to extend the session time for my users. Does any one have a idea where can i do this in IIS ?

Gautam.75801