AS3 Wont work :(

I got Flex 2 SDK and I also have Flash Player 9. I got a HelloWorld example from senoculars tutorial over at

package {
	import flash.display.Sprite;
	import flash.text.TextField;
	public class HelloWorld extends Sprite {
		public function HelloWorld() {
			var display_txt:TextField = new TextField();
			display_txt.text = "Hello World!";

I saved it in and then dragged it over to mxmlc.exe and it created HelloWorld.swf. When I open it up with the player it doesnt show Hello World in the corner. Am I doing something wrong?