Button CreateJs - createjs

Question

Can anyone help me. Can´t make this button work... I used something similar before. I call this GameMenu as a scene inside another JS.
var scene = new game.GameMenu();
scene.on(game.GameStateEvents.GAME, this.onStateEvent, this, true, {state:game.GameStates.GAME});
stage.addChild(scene);
The button is here inside this code:
(function (window) {
window.game = window.game || {}
function GameMenu() {
this.initialize();
}
var p = GameMenu.prototype = new createjs.Container();
p.btnIniciar;
p.Container_initialize = p.initialize;
p.initialize = function () {
this.Container_initialize();
this.addTitle();
this.addButton();
}
p.addTitle = function () {
var titulo = new createjs.Sprite(spritesheet, 'titulo');
titulo.x = screen_width / 2 - titulo.getBounds().width/2;
titulo.y = screen_height / 2 - titulo.getBounds().height/2;
this.addChild(titulo);
}
p.addButton = function() {
this.btnIniciar = new createjs.Sprite(spritesheet, 'btnIniciar');
this.btnIniciar.mouseEnabled = true;
this.btnIniciar.cursor = 'pointer';
this.btnIniciar.x = screen_width / 2 - this.btnIniciar.getBounds().width/2;
this.btnIniciar.y = (screen_height / 2 - this.btnIniciar.getBounds().height/2) + 200;
stage.addChild(this.btnIniciar);
this.btnIniciar.addEventListener("click", function(event) {
console.log("Click not working");
});
}
window.game.GameMenu = GameMenu;
}(window));