Sencha Touch 2 test

reference: http://docs.sencha.com/touch/2-1/#!/guide/first_app

HTML

<link rel="stylesheet" href="http://cdn.sencha.io/touch/sencha-touch-2.1.0/resources/css/sencha-touch.css">
<script src="http://cdn.sencha.io/touch/sencha-touch-2.1.0/sencha-touch-all.js"></script>

CSS

html {
    overflow: hidden
}

.home {
    text-align: center;
}

.home img {
    width: 64%;
}

.home h1 {
    font-weight: bold;
    font-size: 1.2em;
}

.home p {
    color: #666;
    font-size: 0.8em;
    line-height: 1.5em;
    margin: 10px 20px 12px 20px;
}

.home h2 {
    color: #999;
    font-size: 0.7em;
}

.twitterView .x-dataview-item {
    padding: 10px;
    min-height: 50px;
}

.twitterView .x-dataview-item img {
    float: left;
    display: block;
    margin-top: 36px;
}

.twitterView .x-dataview-item h2 {
    font-weight: bold;
    color: #333;
    margin: 0px 0px 10px 60px;
}

.twitterView .x-dataview-item p {
    color: #666;
    margin-left: 60px;
    font-size: 0.8em;
}

/*used in the dataview guide*/
.my-dataview-item {
    background: #ddd;
    padding: 1em;
    border-bottom: 1px solid #ccc;
}
.my-dataview-item img {
    float: left;
    margin-right: 1em;
}
.my-dataview-item h2 {
    font-weight: bold;
}

JavaScript

Ext.application({
    name: 'Sencha',
    launch: function() {
       var carousel = Ext.create('Ext.Carousel', {
       id:'carouselItem',
            fullscreen: true,
       			indicator:false,
            defaults: {
                styleHtmlContent: true
            },
            items: [
                {
                 	xtype:'container',items:[
                 	{xtype:'button',text:'image 1 Next',height:100,
                    listeners:{	
                        tap:function(){
                          var Carousel = Ext.getCmp('carouselItem');
                          var activeItemIndex = Carousel.getActiveIndex();
                         Carousel.setActiveItem(activeItemIndex+1); 
                        }
                     }
                   }
                  ]
                },
                 {
                 	xtype:'container',layout:'vbox',items:[
                 	{xtype:'button',text:'image 2 Back',height:100,width:250,
                    listeners:{	
                        tap:function(){
                          var Carousel = Ext.getCmp('carouselItem');
                          var activeItemIndex = Carousel.getActiveIndex();
                         Carousel.setActiveItem(activeItemIndex-1);
                        }
                     }
                   },
                   {xtype:'button',text:'image 2 Next',height:100,width:250,
                    listeners:{	
                        tap:function(){
                          var Carousel = Ext.getCmp('carouselItem');
                          var activeItemIndex = Carousel.getActiveIndex();
                         Carousel.setActiveItem(activeItemIndex+1);
                        }
                     }
                   }
                  ]
                },
                 {
                 	xtype:'container',items:[
                 	{xtype:'button',text:'image 3 Back',height:100,
                    listeners:{	
                       ...