Phaser + CocoonJs Android Back Button

[mown]

Hello Everybody

 

am trying to write my own code on Android back button , but am facing a problem

here is my code :

 

create: function () {

        Cocoon.App.exitCallback(function () {

            alert('hello');

            game.state.start('intro');

            return false;

        });

}

 

the alert is showing but after that i receive the following error

 

 

thanks a lot guys.