User gets logged out after a period of time.

[chuckles]

Problem:

User is being logged out after a period of inactivity. This inactive time could be an hour or maybe less. How can I prevent this from happening and keep the user logged on for a much longer period?

Here is the environment:

4.7b2 running on a Windows XP system.
user logging into subsonic wirelessly from a Vista based notebook system using Firefox.

Thanks,
A