Hi there, First of all, I would say thank you very much for all who helped me during the past days. Since I am a beginner , sometime I spent even several hours to solve a very simple problem.So, I still need your help in the future. The problem is: ******************************************************** import Random uni :: IO () -> Float uni = do xs <- newStdGen let m = (head (randoms xs) :: Float ) doubleit :: Float -> Float doubleit n = 2.0*n main = print (doubleit uni) ******************************************************** The result is: bash-2.05$ ghci ___ ___ _ / _ \ /\ /\/ __(_) / /_\// /_/ / / | | GHC Interactive, version 5.02.2, for Haskell 98. / /_\\/ __ / /___| | http://www.haskell.org/ghc/ \____/\/ /_/\____/|_| Type :? for help. Loading package std ... linking ... done. Prelude> :cd test Prelude> :l random.ls can't find module `random.ls' Prelude> :l random.hs Compiling Main ( random.hs, interpreted ) random.hs:11: The last statement in a 'do' construct must be an expression Failed, modules loaded: none. Prelude> ******************************************************* What is wrong with it? Thank you very much. Kevin