How do I make my old imac(1999) boot from hard disk instead of cd drive?

Ok so my OLD imac from 1999 keeps trying to boot from the cd drive(I think)instead of the hard drive so of course I can't access the prefs to change this how can I get it to boot from the hard disk without accessing the prefs?

hold down option while starting up, it should present you with a screen where you can choose
which drive you wanna start up from.

Awesome I'll try it in the morn

It didn't work it still shows the little mac guy and flashes between him and a question mark.

hmm, try holding shift during startup. can you boot from any discs?

Are you sure the HD is good?

Well now there my friend from apple is telling me to reinstall Os 9 so I'm gunna do that but I'll see if shift works

Didn't work I'm reinstalling

Option doesn't work on older imacs.
You can use the startup disk control panel from the cd. If it doesn't take, there could be something wrong with the drive, or the battery could be bad.

It does sound like the OS System on your HD has been clobbered. You could try running Disk Utility (or disk first aid) to see if it can repair the disk. If you're installing a pre OS X system, Disk First Aid sould be on the installer cd.

I fixed it but i forgot to post about it. Just needed to be re-installed.