Timeout and passwords

[Rebecca Toohey]

I was wondering if anyone knew of a script or program that timed-out the
browser after every half hour or another fixed period? (I was thinking of
this as a way of moving on patrons after their 30 minute internet session
was up).

Also, does anyone know of a mechanism for providing once-only passwords for
the browser (on a Network)which could be used in conjunction with the
time-out feature above?

If anyone can help, I don't mind receiving replies off the list. I'm a bit
of a newbie - so please excuse my ignorance!!!

Thanks! 

Rebecca