How do i catch giratina in pokemon platinum?!!!!!!!!!!!!?

it is in the distortion world when you get to the spear pillar you will need strength surf (and mabye rock climb) solve the puzzles in the distortion world and it will apperar at the end. remember to save before then either use the master ball or weaken it untill you cant anymore then use as many ultra and dusk as it takes. you may benifit with taking a pkmn that knows a move that will either paralyze it or put it to sleep as it will then be easier to catch