[Haskell-beginners] haskell on snow leopard

Hello, For two past weeks I have been trying to get Haskell working on my macbook pro with Snow Leopard, but unfortunately I was unable to get it. There are some solutions on the internet, but these are mostly useful when you already have ghci and haskell platform installed on your computer, while I can't even get it installed. I have Xcode 3.1 installed, but it seems that it is not the case. Maybe you could recommend any solution to this problem? Sincerely, Bernardas Jankauskas P.S.: I have attached two screenshots of what occurs for me when I am trying to install haskell platform and ghci.