resetting admin password, disc not working

HELP Cannot reformat using disc, unknown admin password

I just got an ibook g4 and I need to reformat it. So I stick in the dvd, restart it, hold down the c button at the appropriate time and all I get is a black screen with a cursor on it that won't respond! So I bootup without the cd, stick it in and click install os x, but I need the admin password before ti can restart and automatically boot for the disc! Any advice? Apples site wasn't any help, their section for 10.3 and 10.4 uses methods only available in 10.4

you can try this:

http://www.tuaw.com/2007/07/17/mac-101-reset-your-mac-os-x-password/

When I get to the point where it asks me for a new password it will not let me type anything. Any other advice?

/sbin/fsck -y [Enter]
/sbin/mount -uw / [Enter]
rm /var/db/.applesetupdone [Enter]
reboot [Enter]

this allowed me to create another admin account but when I restart to bot from the cd (I needed a pasword) it still doesn't boot!

I get a black screen with curser and no response, this si really frusterating

EDIT: Figured it out. Instead of reformatting I just deleted the old account so it's pretty much like new! Does anybody know how to format it so when the customer starts ti up it goes through the setup process?