state0.js

var demo = {};
demo.state0 = function(){};
demo.state0.prototype = {
    preload: function(){},
    create: function(){
        game.stage.backgroundColor = '#DDDDDD';
        console.log('state0');
        addChangeStateEventlisteners();
        game.scale.scaleMode = Phaser.ScaleManager.SHOW_ALL;
    },
    update: function(){}
};

function changeState( i, stateNum){
    game.state.start('state'+stateNum);
}

function addKeyCallback(key, fn, args) {
    game.input.keyboard.addKey(key).onDown.add(fn,null,null,args);
}

function addChangeStateEventlisteners() {
        addKeyCallback(Phaser.Keyboard.ZERO, changeState, 0);
        addKeyCallback(Phaser.Keyboard.ONE, changeState, 1);
        addKeyCallback(Phaser.Keyboard.TWO, changeState, 2);
        addKeyCallback(Phaser.Keyboard.THREE, changeState, 3);
        addKeyCallback(Phaser.Keyboard.FOUR, changeState, 4);
        addKeyCallback(Phaser.Keyboard.FIVE, changeState, 5);
        addKeyCallback(Phaser.Keyboard.SIX, changeState, 6);
        addKeyCallback(Phaser.Keyboard.SEVEN, changeState, 7);
        addKeyCallback(Phaser.Keyboard.EIGHT, changeState, 8);
        addKeyCallback(Phaser.Keyboard.NINE, changeState, 9);
}