How do you use fly on Pokemon platinum?

Answer 1

Have a bird Pokemon with you. (examples: starly, staravia, staraptor, I think chatot too . .) Open up the menu. Go to Bag. Now go to TMs. Scroll down to the HMs and select fly (If you have it). Teach it to a Pokemon with ABLE! under it's name. Delete a move, and close the bag. Go to "Pokemon". Select your bird. Now, a list pops up. The second or third one should be fly. You need a certain badge to use it out of battle. If you have that badge, select fly and then choose a location on the map. The only cities you can fly to are ones you've been to before. Happy Flying!