CD stuck in iBook G4

I have an mid-2005 iBook G4 that runs Ubuntu 11.04 (upgraded from 10.10 PPC buuild). When i tried upgrading it to 11.10. It failed and whenever i try to boot it it shows the 11.04 logo, then just goes blank with the backlight. I have a custom desktop running 12.04 Ubuntu. I accidentally inserted the one from the desktop instead (the cd is x86 only) and when i try to boot from cd, it just restarts. I have the 10.10 PPC CD and a 10.4 restore CD too.

Thank You for your consideration.

PS.

i have tried holding down the mouse button,and hulding down the f12 button too