html - asp session timeout not working properly -

i want sessions not disappear after default 20 min wrote code

    <%   session("userid")=rsguestbook("userid") session("titleoftheme")=rsguestbook("titleoftheme") session("compare")=rsguestbook("compare") session("thecontect")=rsguestbook("thecontect") session("lastupdate")=rsguestbook("lastupdate") session("requestid")=rsguestbook("requestid")  userid=session("userid")  session.timeout=600 %> 

in asp file somehow still 20...

<% response.write(session.timeout) %> 

it shows me 600 correspond 20

i did read few answers here found nun answer why , else missing in code glad quick fix , no don't want use cookies.

answer : server side fault or better "recycle pool" make longer clean , sessions hold longer

if site low traffic application pool might recycle after 20 minutes. setting higher "idle time out (minutes)" in advanced settings of associated application pool might help