How do you catch rayqauza in pokemon emerald?

you can catch raquaza by going to pacifidlog and surfing east past the boy and girl, then go straight until you hit a small gray rock, then go down a few spaces, then go east and you'll see three brown boulders. Go two steps past them and go up through the zigzag of rocks and you'll see an island! That's the Sky Pillar! Then go into the cave, and up the ladder and you'll see the pillar. Go in and you will up the pillar. Then you see rayqauza. (You don't get to battle him until you see him stop Groudon and Kyogre fom fighting. And when you go to get him there will be rocks in the pillar and you will need your mach bike to get over the cracks. When you get to the floor with the cracks that look like this, x xx x, go to one of the ones in the middle and you will fall through to some steps, go up them and you will be at rayqauza! I would suggest saving before you battle him and not to use your master ball. I caught Rayqauza, Groudon and Kyogre all with ultra balls. Buy 80 or so. (you'll need 'em!) And P.S: You Don't have to have beaten the elite four to get rayquaza, but you have to to get groudon and kyogre. To get them you have to talk to the weather man at the weather institute. By Yohiggins!