Eminem--> Ja Diss

do you know what this song is called? its a diss by eminem where in the chorus he says
"if pac were still alive he wouldnt ride wit ja
na na na na na na na na"

i already downloaded it but i forget which one it is. i have too many songs. ne1 know?
also, is it on the new green lantern mixtape?
thanks. :P

eminem / 50 cent / busta rhymes - hail mary (remix)

and btw its "if pac were still here now"

thanks.