How do you defeat the Dragon in Kingdom Hearts

Okay... I know that answer is explanatory, but this is a bit better. After defeating Riku in the entrance hall, you will gain the Strike Raid ability. When you first face the Dragon, first jump, the glide over to the dragon's back. The reason why you must do this is because the Dragon will attack right in front of it. Once you are on the Dragon's back, lock on to the head or neck. Once you lock on, the last command on the command list will be some thing called "Raid". Use this several times, and then "Raid" will turn into "Judgment". Use this, and it will have lots of effect on the Dragon. When the Dragon is about finished, (and if you're still on the Dragon's back) it will try to shake you off. It's going to be hard to get back on, so go towards the chest and use "Ars Arcanum". This will probably defeat the dragon.