How do you get firestone in Pokemon HeartGold

You can get it any of these ways:
1. Trade in the points you've earned in Pokeathelon Dome on Tuesdays.
2. Win first place in the Bug Catching Contests. (The top prize varies every time)
3. A trainer on Rt. 36 will sometimes call and say he has one for you.
4. Show Bill's grandfather a Growlithe. (Rt. 25)
5. Dousing Machine on the "Warm Beach" course in the Pokewalker. (random after 5000 steps)