need help getting d/p to work

i got 2 questions to ask1.i got the no$gba emulator just 1 issue when i get pokemon diamond on it ,it says data could not be read please re insert catrtidge
how can i fix this?i need to know how to fix this and if there is a better rom2.can there be wi-fi in the game
like go on gts and trade on it

1) search the forum, theres a sticky on this.