import mx.controls.Alert;
import mx.styles.StyleManager;
import mx.events.StyleEvent;
private var lastCSS:String;
private function changeCSS( name:String ):void{
unloadCSS( false );
var styleEvent:IEventDispatcher = StyleManager.loadStyleDeclarations( name, true );
lastCSS = name;
}
private function unloadCSS( updateFlag:Boolean ):void{
if( lastCSS )
StyleManager.unloadStyleDeclarations( lastCSS, updateFlag );
}