OT: Powerbook Problem.

[pixiedave]

Hope someone can help!  When I boot my powerbook, my desktop image
loads, and then the apple bar starts to load, then the rainbow wheel
keeps spinning, and the apple bar keeps flashing on and off as iif it
is trying to load.  A disc will eject with the eject button, and the
volume buttons work including the display, but the os never finishes
loading.  So I want to reinstall, but how do i get the g4 to boot from
the install dvd without having the machine up and running, installing
the disc, choosing install and rebooting?  I imagine there is a key
sequence, but cant find it
-- 
"You Never Blow Your Trip Forever" Daevid Allen