[flexcoders] simple SimpleButton

[[EMAIL PROTECTED]]

How do I add the button to the application?
addChild does not seem to be available
this->addChild(newButton); and addChild(newButton) both produce
TypeError: Error #1034: Type Coercion failed: cannot convert 
flash.display::[EMAIL PROTECTED] to mx.core.IUIComponent.

<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"; 
creationComplete="onComplete()">
 <mx:Script>
        <![CDATA[
           
            import flash.display.Sprite
            public function onComplete():void
            {
                var newButton:SimpleButton = new SimpleButton();
                // add child here
                .
            }
           
           
        ]]>
  </mx:Script>   
</mx:Application>