You cant catch diaglia or palkia.
The only way is the arceus event. When it comes out you get to choose diaglia, palkia or Giratina.
That sucks^
if you get arcius and go to the ruins you can chouse betwien palkia, diaglia, girancha.i got palkia and arcius from pearl i am waiting for blackCheck out soul silver legendaries on serebii.net. I think you can, but it is very hard and it is after you get 16 badges and beat red who by the way has a level 88 pikachu or something.
Go to the Ruins of Alph
Palkia holds the Lustrous orb, use the move 'Theif' in battle, or catch Palkia and retreive it.
you dont
you can but you need an arceus then go to the ruins of alph into the small lab and then you can get a giratina,digla, or palkia
Mt.Cornet
From what I know, no. To see Palkia on Diamond or Pearl, catch or trade. Hope I helped. Sorry.
There is one event and you have to have an arceus but you can only get one of them and they are level 1. It is the Arceus Event.
You can't catch charizard in Pokemon soul silver. You can get a charmander from professor oak.
you dont. you trade it from platinum , diamond or pearl
Well You Can Catch:
its in mt silver.