title: flex 4 center element in a group
body: <p>I am playing around with flex 4 GUI with a simple alignment but couldnt figure out why.</p>
  
  <p>I have button1, button2, and a text field. I want to align them horizontally, and center vertically for the text. 
  For the following code, i see the following output.</p>
  
  <pre><code>_______   ______
  |bt1   | |bt2   |   text1
  |______| |______|     
  </code></pre>
  
  <p>my question is;
   1) why with the properties i sent on btn 1 verticalCenter="10" and btn2 verticalCenter="-10" they are still aligned? shouldnt i see one is up and the one is donw?
  2 ) why my text1 is aligned top, even though i set it to verticalCenter=0, i tried it with or without in a group.</p>
  
  <p>Thanks guys</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark"
      xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955"
      minHeight="600"&gt;
      &lt;fx:Declarations&gt;
          &lt;!-- Place non-visual elements (e.g., services, value objects) here --&gt;
      &lt;/fx:Declarations&gt;
      &lt;s:Group minWidth="100"&gt;
          &lt;s:layout&gt;
              &lt;s:HorizontalLayout/&gt;
          &lt;/s:layout&gt;
          &lt;s:Button label="myButton" click="" horizontalCenter="0"
              verticalCenter="10"/&gt;
          &lt;s:Button label="myButton" click="" verticalCenter="-10"/&gt;
          &lt;s:Group verticalCenter="0" horizontalCenter="0"&gt;
              &lt;s:Label text="hello" color="#FFFF" verticalCenter="0"
                  textAlign="center" /&gt;
          &lt;/s:Group&gt;
  
      &lt;/s:Group&gt;
  &lt;/s:Application&gt;
  </code></pre>