なるほど、こんな感じなんだ
function contentsEnterFrame():Void{
content_mc.flag = true;
content_mc.onEnterFrame = function():Void{
var dis:Number = this.goalY – this._y;
if(this.flag || Math.abs(dis)>1){
this._y += dis * friction;
}
else{
delete this.onEnterFrame;
}
};
}