How do you evolve Evee?

In Pokemon Diamond, Pearl, and Platinum, if you want to evolve your Evee to a Leafeon you go to the Eterna Forest You will have to level up your Evee there and once it levels up by one level, it evolves to a Leafeon. If you want a Glaceon, you level up eevee on route 217. To get a Flareon, you give Evee a Fire stone. For Vaporeon, you give it a Water stone. And for a Jolteon, you need a Thunder stone.