is it possible to put more than one rom on a gba cart?

[luicfershalo]

Before crying to the wolves about piracy
I want to tell that I respect peoples work
but also like to simplify my life when I can
I have 22 nintendo original DS games
and now that the possibility of not carrying them around with me is offered
I grab it
I mean, I have a Flash2 advance ultra of 1G and a superpass
I would like to put more than one DS rom on my GBA flash cart
I tried yesterday but it didnt work
do I have to include a program like a boot file or something?
thanks for your help...

[souLLy]

this is piracy and not to be discussed here. If you have issue with it pm an admin who will explain the situation to you.