我新建一个场景，然后通过一个按钮将另一个Scene push过来，然后pop掉，再次调用该push函数的时候就报错了，这是为什么？
void HelloWorld::menuCloseCallback(Ref* pSender)
{
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WP8) || (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT)
MessageBox(“You pressed the close button. Windows Store Apps do not implement a close button.”,“Alert”);
return;
#endif
Director::getInstance()->pushScene(MyHelloWorldScene::createScene());
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
exit(0);
#endif
}