<mx:Canvas width="100%" height="100%" backgroundImage="{panelBg}" backgroundSize="100%">
    <mx:Panel 
     title="Main Panel" titleStyleName="myTitleStyle" headerHeight="25"
     backgroundAlpha="0" dropShadowEnabled="false" borderAlpha="0"
     width="100%" height="100%">
     <mx:Text styleName="myFirstStyle" text="Hello Friends of Ed!"/>
     <mx:Text text="CSS is neat!"/>
    </mx:Panel>
   </mx:Canvas>
   
  </mx:Application>