This may be confusing. I know. To transfer pokemon from Gen 4 to Gen 5, you turn on the DS with the B/W game, go to the place where you recieve Gen 4 pokemon, talk to the person that you want a pokemon import, then turn on the DS with the D/P/Pt/HG/SS game. On the menu screen, select "Connect to future game". The Gen 5 game will detect a Gen 4 game and then communicate with each other. Then you can send your pokemon to the Gen 4 game to the Gen 5 game. You can do up to 30 at a time. After it's done, your Gen 4 pokemon will be stored in a box.