Hmm, I know a great tut for that but the TOS prevents me linking it here directly.

Sorry to come off as rude but you should try to google it as it will be more direct than asking here.

Try this open google and type "Dreamlight 3D emissive" and a tut should come up called "Yours To Copy Now - Basic 3D Training" which covers emissive surfaces in DS and Iray.