package { import flash.display.Sprite; import flash.events.Event; public class animation_ch05_Velocity2 extends Sprite { private var ball:animation_ch05_Ball; private var vx:Number = 5; private var vy:Number = 5; public function animation_ch05_Velocity2() { init(); } private function init():void { ball = new animation_ch05_Ball(); addChild(ball); ball.x = 50; ball.y = 100; addEventListener(Event.ENTER_FRAME, onEnterFrame); } private function onEnterFrame(event:Event):void { ball.x += vx; ball.y += vy; } } }