Boot up issues G4

[p521us]

Hey all i have the Powerbook G4 and when i boot it up it takes me to the greyish screen with the apple and the spinny geat thing. then it all stops and says "sh-2.05s#"

i read on this forum to type "exit" to leave the promt and some codes pull up and then the "sh-2.05s#" reappears

then i do the "FSCK -y" command it it runs some other codes and ends in
"cannot repair volume whtn it is mounted with write access
The volume hh could not be repaired"

any clue as to what i would do next?
(im running lepard 10.2 something)

Thanks!!!
Nathan(new mac user)