--- Stephan Zaubzer wrote: data Entry a = EmptyEntry | MakeEntry a a showEntry :: (Show a) => Entry a -> String showEntry EmptyEntry = "Empty" showEntry MakeEntry a b = show a ++ ": " ++ show b --- end of quote --- That's a good start. All you need to do now is make Entry an instance of the Show class:

instance (Show a) => Show (Entry a) where show = showEntry

Also, you have a small syntax error in showEntry - you probably want:

showEntry (MakeEntry a b) = show a ++ ": " ++ show b

Finally, using ShowS is generally better for this kind of thing. <http://www.haskell.org/tutorial/stdclasses.html> describes the disadvantages of using repeated appends and the advantages of ShowS. Hope that helps! /gXm