How can you catch chansey in Pokemon FireRed?

Well, I know how to catch in Pokemon FireRed but not in LeafGreen. In FireRed, you go to the Safari Zone. Go to the right side on the zone, and find Chansey there. And when you find one, throw a rock because it's easier to catch if you throw a rock than a bait. Then throw a poke' ball. But sometimes it goes away... It takes luck to find it. Be patient.

Remember!

1. If you throw a rock, it's easy to flee but easier to catch, but if you throw a bait, it's harder to go away but harder to catch.

2. Chansey is always at the right side!

Goodluck,

There is a man in a rest room who says he has caught a chansey but he does not say which area
safari zone