title: extjs - center a formPanel on a normal panel
body: <p>I'm using extjs and just trying to solve a simple problem:
  I have a form with a fixed width. I want to Center this form within a normal Ext.Panel.
  I'm trying to achieve this the 'css-way' - setting the left and right margin to 'auto'.</p>
  
  <p>But this doesn' work, it seems the margins are just ignored.</p>
  
  <p>The Code:</p>
  
  <pre><code>var curStateForm = new Ext.FormPanel({
      title:'test',
      width:300,
      bodyStyle:'margin:5px auto 0 auto',
      items: [edIst, edAdjust, edSumme]
  });   
  
  
  var testPanel = new Ext.Panel({
      width: '100%',
      frame:true,
      items: [curStateForm]
  });  
  </code></pre>