Life of Session variable?

[SIZE=1][ASP/MSAccess][/SIZE]
[SIZE=1]In my website it is set that session expires around 20min. Sometimes it become too irritating, when person is reading some article and then sending his comment in given txtfield. Because session expires and he is redirected to Relogin Page.[/SIZE]

[SIZE=1]How 2 Avoid This Problem?[/SIZE]

[SIZE=1]Can i store the session value in some hidden field, in the “comment FORM”.[/SIZE]

[SIZE=1]Or some any other way?[/SIZE]

[SIZE=1]Thanks(“Advance”)[/SIZE]