add something to a list

Hi, I'm a poor lonesome newbie in Haskell world, and I would like to add a string typed on the prompt to a list of strings which is already defined. It would look like something like : type Path = [String] currentPath::Path currentPath = [] getpiece ::IO String getpiece = do c <-getLine return c putpiece:: String->Path putpiece a = a:currentPath and then I could combine the two functions, but obviously it doesn't work. I dare understand that it's impossible isn't it ? Maybe the only way is to create a new [String] each time I want to add a new string ? No ? Christophe Certain