list of results monad

hi, I'm trying to build a monad that will give a list of results. this is what i want to be able to do I have data M a = I [a] instance Monad M where return x = I [x] I (x:xs) >>= f = ?? The type of >>= is m a -> (a -> m b) -> m b but here the input is [a], now if I apply the input individually on f then i can get a [m b] and if i extract at each step then I can get [b] and then if i say return ([b]) i get m b.. right ?? Is this how I go about it .. if so can you give me a small code snippet of how to do that. Thanks, gmu _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.