package import flash display Sprite import flash external public class

package {
	import flash.display.Sprite;
	import flash.external.*;

	public class Main extends Sprite
	{
		public function Main()
		{
			if (ExternalInterface.available){
                ExternalInterface.addCallback("sayHello", sayHello);
            }
		}
		public function sayHello(msg:String):void{
			ExternalInterface.call("alert",'Answer from Flash:' + msg); 
		}
	}
}