How to find out which OS I have?

I used to have OS 9 with my Titanium powerbook G4 .

Then I tried the software upgrade this morning to OS X.

Now How do I know it is Actually upgraded to X?

the UI doesn't really 'tell' a difference.

Alright well you probably are not booted into OS X because the difference is without a doubt noticeable. You should be able to in the System Preferences select the OS X folder as the boot folder. I never used OS 9 so I am not too sure the exact methods

Upgrading to OX panther is not free, right?

No you need to buy it

OS 9 UI is DEFINITELY way different from the OS X UI, you would see the difference immediately.
You cannot upgrade OS 9 to OS X, but you can have both system installed, which happens when you install OS X on a Mac that already had OS 9 installed.
If I remember well, you need to go to the Apple menu and open the control panel. In there you should find "Startup disk". There you can set the OS X folder as boot folder, and at the next reboot you are in OS X.

To simplify my questions, please answer these questions straight up:

1. How do I find out what OS do I have?

2. Under my System Preferrence->System->Startup Disk, there are two items only: Mac OS X 10.2.8 on Macintosh HD, Network startup.
Does it mean I only have OS X?

sorry if it sounds rude, but I am not, just try to get the straight answer.

Apple menu > About this mac

thanks

yeah that works for osx and osc (os classic).

but your system disk should be checked before your bother upgrading... cus if you have another OS on there higher than the one ur currently using.. no point in upgrading a lower os.