Session timing out after 20 minutes

[Serge]

Good Day,

I've hard coded a session timeout of 480 minutes when the user logs in, but
the session times out after 20 mins. There is no web.config file at the root
of the web site or the application folder, as I prefer to set in code. Any
ideas why it's ignoring the session.timeout command ?

Session("menuAppUserid")=p_userid
Session("menuAppPassword")=p_password
Session.timeout=480