title: How to execute the javascript in tabpanel item in ExtJS4?
body: <p>I'm building a website that use ExtJS, once I click a button<br/>
  it calls Ajax to load a html page, and add it to tabpanel as an item.<br/></p>
  
  <pre><code>mainTab.add({
      xtype: 'panel',
      html: ajaxResponse.responseText
  })
  </code></pre>
  
  <p>But the javascript in that html page does not execute , <br/>
  how to solve this problem? Thanks very much!</p>
  
  <p><b>EDIT</b>
  It seems I have found it out， any better solution is welcome:</p>
  
  <pre><code> mainTab.add({
      html:'&lt;iframe src="'+UrlText+'" frameborder="0" scrolling="auto"&gt;&lt;/iframe&gt;'  
   })
  </code></pre>