How to get Rotom and his forms in pokemon platinum.

For Rotom you must go the Old Chateau. (it must be midnight) in the Old Chateau is a TV.
Talk with it and Rotom will come out and fight with you. >>(YOU MUST HAVE DONE THE ELITE FOUR)<<
Warning! Rotom has a low lvl so watch out.

For his forms you must have the Japanese event of 28 september 2008. from that event you have a key. with that key you can open a secret door in the HQ of Eterna city.

This is not my foto!

In the room you've opened are 5 red things:
1 - furnace: Heat form (Overheat move)
2 - aerator: Spin form (Air Slash move)
3 - fridge: Frost form (Blizzard move)
4 - washing machine: Wash form (Hydropump move)
5 - lawn mower: Cut form (Leaf Storm move)