You can't. The maximum is 4. for more info, see www.psypokes.com/rs/faqs.php
how to get a jirachi
^^Yes, the maximum is 4 for emerald, and to get it, you must do the following:
--Beat the Elite Four
--Complete the Hoenn (not national) dex
--Win Master Rank in all categories for the Pokemon Contest in Lilycove
--Earn all the Gold symbols at the Battle Frontier
Chat with our AI personalities
The stars on your trainer card have absolutely no use whatsoever except for showing off to others. The stars also change the color of your trainer card.
Pokemon's ID is your Trainer Card ID!
you train every single Pokemon in the national dex to level 100, and then you've beat the game, congrats
the last thing to do is on your trainer card, you have stars. Get for stars then go to mossdeep and take the rocket to the moon. There you may catch deoxyes and jirachi.
The black card is your trainer card with I think 5 stars