晴天日記這個世界，沒有想像中的簡單，也沒想像中的那麼困難。

最簡單的tween效果，會從舞臺0的位置，移動到480的位置

import fl.transitions.Tween;
import fl.transitions.easing.*;
var myTween:Tween = new Tween(taipeier_mc, "x", Regular.easeOut, 0, 480, 3, true);

不斷重復來回tween
如果覺得 Regular 效果不夠明顯，可以改成 Strong，效果會更強烈一點

import fl.transitions.*;
import fl.transitions.easing.*;

var myTween:Tween = new Tween(taipeier_mc, "x", Regular.easeInOut, 0, stage.stageWidth, 3, true);
function gotoFinish(event:TweenEvent):void{
myTween.yoyo();
}
myTween.addEventListener(TweenEvent.MOTION_FINISH, gotoFinish);

http://help.adobe.com/zh_TW/ActionScript/3.0_ProgrammingAS3/WS5b3ccc516d4fbf351e63e3d118a9b90204-7dca.html

import flash.geom.*;
var pt1:Point = new Point(circle1.x, circle1.y);
var pt2:Point = new Point(circle2.x, circle2.y);
var distance:Number = Point.distance(pt1, pt2);