I put the wrong resolution on my Mac

HELP! I put the wrong resolution on my mac, which is a mac mini(really old one). I bought this mac when the mac mini releases about 3 years ago. However, I put the wrong resolution on my mac, and my screen said 'OUT OF RANGE", apprently I put the wrong resolution on the mac which let my screen unable to display its stuff.
I really need help, this mac is my only computer, need help quick!
MY computer had no virus and stuff like that. Surely, I put the wrong resolution my mac and caused this problem!
HELP!

I'm not sure how SAFE MODE works in OS X having never used it, but if you hold down shift key while booting, it boots into safe mode. I would assume the safe mode would have a lower resolution...

First of all, welcome! Second, shut it down, you may have to pull the plug which isn't a great thing to do, but you are running low on choices. Restart and hold the following four keys:
Apple Option P R
You will be rewarded with the startup chime, keeping holding down the keys until you hear the chime three times.
Good luck!

Thomas if you are using X.0, which was a beta format system, suggest updating software to Tiger X.4.

About the OS vertion and Safe mode

About the OS bvertion, I checked and found that it was 10.3.1 and not 10.0.
And for the safemode thing, I went sucessfully into the safe mode, however I could only change Safe mode's resolution and not the normal's mode's resolution.
Please teach me how to change normal mode's resolution in safe mode.
For clicking Apple, Option and P,R and didn't do any thing but boot into my OUT OF RANGE OS. Do I have to wait? Or I was supposing to keep pressing them when booting?

Command+Option+P+R is a PRAM (perimeter Ram) reset. You hold all 4 keys together right at the startup sound. You keep them down and let it restart and do the startup sound 2 more times, then you let go. If that does not work let us know. It resets the firmware to stock and on the older G4 systems I have tried it on, reset the resolution to a low level.

After trying what was suggested earlier in this thread, I would seriously install the Combo update to bring your system to 10.3.9: that version was rock solid stable and very nice to use.

And if I recall correctly, 10.3.1 had a big issue with external FireWire hard drives where it would corrupt them if any install was underway with the hd plugged in. Besides, 10.3.1 till about 10.3.7 was very very flaky.

Another reason Thomas if you go to Leopard to do a clean install and not piggy back any of these problems with you.