can't reset password

i'm aware that similar stuff has been asked before, here and elsewhere, but i still haven't understood the answers. while trying to reset the password (placing the installation cd, restarting, pressing c, choosing language and changing password, i forgot to press reset, typed in my new password and took the cd out mistakenly.

now, everytime i start the computer i have a box asking for my password, the new password does not work, the old one i don't know what it was, and the cd procedure (restarting, pressing c, etc) doesn't work any longer as the screen keeps asking for my password. how can i get out of this mess. please help. never used macs before.

Let's do a PRAM reset first: (Taken from the Apple KB article)

Resetting PRAM and NVRAM

1. Shut down the computer.

2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.

3. Turn on the computer.

4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears. Hold the keys down until the computer restarts and you hear the startup sound for the second time.

5. Release the keys.

After doing the above, insert your install DVD and restart the machine. Hold down the OPTION key as soon as you hear the chime. Let it go once you see the Apple. Choose the startup disk and press enter.

If everything goes well, you should be able to reset the password this time.