you probably got it pointed out in haskell-beginners, but in case not:

On Thu, Nov 27, 2008 at 7:10 PM, abdullah abdul Khadir <abdullah.ak2002@gmail.com> wrote:
a) I need to put a do after else for more than one instruction (?)
 
No, the do thingy is a syntactic sugar for chaining "warm, fuzzy" (the "preffered" wannabe-joke-term for the presumably scary term monads/monadic) operations.
 
it allows you to write in "classical" imperative/sequential style instead of chaining operations manually (using the >> and >>= operators, which the do notation translates into anyway). lookup some monad tutorials/docs.
 
you are right in that if there is only one operation, no transformation is needed, so the do is unnecessary.