動かす練習です

/**
 * Copyright plus-tic ( http://wonderfl.net/user/plus-tic )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/ab23
 */

package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    public class Main extends Sprite {
        private var player:Sprite;
        
        public function Main() {
            player = new Sprite();
            player.graphics.beginFill(0xFF0000);
            player.graphics.drawCircle(0,0,20);
            player.graphics.endFill();
            player.x = player.y = 200;
            addChild(player);
            
            addEventListener(Event.ENTER_FRAME,ET);
            stage.addEventListener(KeyboardEvent.KEY_DOWN,OSU);
            stage.addEventListener(KeyboardEvent.KEY_UP,HANASU);
                        
        }
        
        private const SPEED:Number = 10;
        
        private var left:Boolean = false;
        private var right:Boolean = false;
        
        private function OSU(e:KeyboardEvent):void{
        		//キーが押されるとOSUが呼ばれるので、変数にtrueを代入
        		if(e.keyCode == 37)left = true;
        		if(e.keyCode == 39)right =true;
        }
        
        private function ET(e:Event):void{
        	if(left)player.x -= SPEED;
        	if(right)player.x += SPEED;
        }
        
        private function HANASU(e:KeyboardEvent):void{
        if(e.keyCode == 37)left = false;
        if(e.keyCode == 39)right = false;
        }
        
    }
}