u need to check whether it's ac or dc btw, should be stated right behind the 100V(here).
if it says 100V, and the adaptor given is 100V, then it should work fine. wad's the worry besides the polarity?
as long as the polarity is right (center negative or center positive), and there's more current than required(that means >500ma) at 100V(ad or dc?) then it should be fine.