My dog used to be the same and he was sh1t scared and cowers in the corner he is not as bad now as a few years ago we got a cd of firework noises and played it and got him used to associate the noises with a treat.
Dogs think that the noise is danger and are worried for their owners and get upset because they think the noises are going to hurt their owners so the important thing is to not make a fuss and ignore it and just do as you would normally do.
Also I know this might sound a wind up but get some barks rescue remedy from the chemist it is fairly cheap and it does calm dogs down and is completely herbal just a few drops is enough and dogs seem to love the taste of it.
Anyway heres a pic of my dog.
http://i206.photobucket.com/albums/bb96/knobby nonuts/knobbyinwig.jpg