error 1120 Acess of undefined property with simple program !

I am new to flash and this error keeps happening and i don't know what is wrong with code i'd be glad if i got helped here is my code

package code

{

  import flash.display.Sprite;

  import flash.text.TextField;

  import flash.text.TextFormat;

  import flash.display.MovieClip;

  public class Example extends MovieClip

  {

  public var answer:Number = 42;

  public function showGreeting():void

  {

  var message:String = "Hello, world!";

  trace(message);

  }

  var myTest:Example = new Example();

  myTest.showGreeting();

  }