title: Nothing displaying on starting app sencha touch
body: <p>I am using sencha 2.3.1 and the following code (in app.js), to display some html content on page. But nothing is being displayed. Please tell where I am wrong.</p>
  
  <pre><code>Ext.application({
      name: 'Sencha',
  
  
      requires: ['Ext.tab.Panel'],
  
      launch: function() {
          //The whole app UI lives in this tab panel
          Ext.Viewport.add({
              xtype: 'tabpanel',
              fullscreen: true,
              tabBarPosition: 'bottom',
  
              items: [
                  // This is the home page, just some simple html
                  {
                      title: 'Home',
                      iconCls: 'home',
                      cls: 'home',
                      scrollable: true,
                      html: [
                          '&lt;img height=260 src="http://staging.sencha.com/img/sencha.png" /&gt;',
                          '&lt;h1&gt;Welcome to Sencha Touch&lt;/h1&gt;',
                          "&lt;p&gt;Building the Getting Started app&lt;/p&gt;",
                          '&lt;h2&gt;Sencha Touch (2.0.0)&lt;/h2&gt;'
                      ].join("")
                  }
  
                ]
  
             })
  
          }
  
  });
  </code></pre>