Help!!best emulator for pokemon diamond..

hi,can anyone give me the link to a good emulator for playing pokemon diamond,i have been playing for it in my ds..but i also want to try playing in the emulator..and one more thing?can i battle pokemon from emulator to nds??

Second thing isn't possible at the moment. no$gba is by far the best NDS emulator, search the Forums for "no$gba 2.6a", which is the latest version.