title: add an iframe to container in extjs
body: <p>I want to add my javascript generated iframe to a panel. this is extjs 4.x version and I am new to extjs
  here is my code to get the panel and container</p>
  
  <pre><code>function generatePanel(){ 
  ....
  ....
      var thecontainer = Ext.create('Ext.form.FieldSet', {
              title: "my container",
              labelWidth: 1,
              bodyStyle: "padding-right:5px;padding-left:5px;",
              layout: 'anchor', 
  
          });
  
  var ifrm = document.createElement("iframe");
      ifrm.setAttribute("src", "http://google.com/");
      ifrm.setAttribute("name", "myIframe");
      ifrm.style.width = "640px";
      ifrm.style.height = "480px";
      document.body.appendChild(ifrm);
  
  ....
  }
  </code></pre>
  
  <p>this works fine but the iframe is not within the container. it shows up at the bottom of the page. What am I doing wrong?</p>