[Moo] Initialize a function in a class

[ghazal]

Hello,
in this class,
http://www.jsfiddle.net/DTtNa/2/

if you look into it, you will see that I have troubles to pass a
function through initialize, function that will be be defined later.
In this part :
/***/

                els.each(function(el) {

                    var conteneur = el.createConteneur();
                    if (conteneur) {
                    conteneur.mh = conteneur.clientHeight;
                    conteneur.mw = conteneur.clientWidth;

                    var myFx2 = conteneur.createFx();
/***/

I tried to create this :
var conteneur = el.createConteneur();
and this
var myFx2 = conteneur.createFx();

The 2 functions
createConteneur and createFx are defined in Element.extend

Do I completely misunderstand the inner structure of a Moo1.2 class ?
Any help will be welcomed.
PS: this is an update of a moo1.12 dropdown for a menu in Joomla