Hello, in order to get familiar with keyboard data entry, i'm writing a program for the well-known Hangman game. Each entry must change several lists (letters found and remaining letters). I have three main difficulties with data entry : First When i enter a letter (A) , i get a good response (displaying old word and letters, message "guess ok") and an unattended one that says "guess false", thus displaying the result from my entry. I don't understand why the process seems to execute twice, the fisrt one being correct, the second not. Second difficulty : the "procedure" for data entry is written twice ("guess a letter ..." prompt). I think it would be a good idea to write it once as a "function" that would display the prompt then get a character from the keyboard. Third difficulty : in both cases (guess ok or false), i have to ask for a new entry; to avoid writing this twice again, i write it before the recursive calls of process_guess. Writing a function would perhaps allow to call it directly as a parameter of process_guess ? Being new to haskell, recursive functions now seem clear to me but i feel that IOs make writing a program more difficult. And i've not yet tried data base access... Please, say me if the way i wrote my program is a good or bad approach. Below an example of a run : Here's my program. Could you help me. Thanks, Didier solution="HANGMAN" word="H-----N" letters=['A'..'Z'] hangman = do -- enter a letter putStrLn "Guess a letter (9 to end):" guess <- getChar -- process process_guess guess letters word process_guess pg pletters pword =do let pguess = toUpper pg putStrLn pword putStrLn pletters if pguess == '9' then do putStrLn "Done" else do if pguess `elem` pletters then do putStrLn "Guess OK \n" else do putStrLn "Guess false \n" -- Enter a new letter before going on, in both cases putStrLn "Guess a letter (9 to end):" guess <- getChar if pguess `elem` pletters -- guess ok -> remove guess from available letters then add guess to word then do process_guess guess (newletters pletters pguess) (newword pword pguess solution) -- guess false -> remove guess from available letters, leave word unchanged else do process_guess guess (newletters pletters pguess) pword newletters l g = filter (/= g) l newword [] _ _ = [] newword (w:ws) g (s:ss) = if w == '-' then if s == g then g : newword ws g ss else w : newword ws g ss else w : newword ws g ss toUpper c | isLower c = toEnum (fromEnum c - fromEnum 'a' + fromEnum 'A') | otherwise = c isLower c = c >= 'a' && c <= 'z'