Which Pokemon games can you use to trade onto Black and White?

I know that in Pokemon Black and White you can trade pokemon to your Black and White game when you finish the game. However I don't have any Nintendo DS pokemon games (besides Black/White) , so I was wondering if I could trade pokemon from games such as silver?|||You can't trade to any other pokemon games but you can do a one way permanent transfer with heart gold, soul silver, platinum, diamond and pearl in much the same way as the pal park works, except you need two DS systems|||you can trade pokemon between black and white at any time after a certain point in the story when it lets you access the second floor of the pokemon center.





after you beat the game there is a building that you can enter on route 14 i believe and there is a scientist that that asks you to help him with a project. you can only help him if you have all the badges and beat the game.





you can transfer pokemon from HG,SS,Diamond, pearl, and platinum, into black and white but one you do you cant move them back. its like migrating pokemon from the GBA games into DS games.