Haskell problem

[zanga]

I need to make a write to file filter function that takes the comment tokens from a list and write's it to a file
so I made a function that tells me if it's a comment or not
isComment :: Token -> Bool
isComment (Tok s r c k) = if k /= Comment then False else True

And a function that takes the comment and write's it in a file
writeComments :: [Token]->IO()
writeComments (t@(Tok s r c k) : ts) =
if isComment t then writeFile "com.txt" (s)
else writeComments (ts
But it only takes the first comment token:(...Help please...