Display enum in a RadioChoice

[Gervais]

Hi all,

I need to display a enum in a RadioChoice. So i'm doing that :
   public static enum Genre { Male, Female }
   private static List GENRES = Arrays.asList(Person.Genre.values());
   ...
   add(new RadioChoice("student.genre", GENRES));
   ...

It work but displaying avlues Are "Male" and "Female" and i'm french so 
i prefer "Masculin" and "Feminin" or (better in my case) "M" and "F".
I don't need to overload toString in my enum because i think Genre is in 
the model and my model doesn't have to change with langage.

->  How can i render "M" or "F" instead of "Male" or "Female" ?

Thanks