when i have three SceneManagers, i can't see the myui

I create mygui buttons in the SceneManager 1.When i go to the another SceneManager, I can't no see the buttons.
How to make them seen?


std::string fontname = OgreFramework::getSingletonPtr()->getMyFont()->getFontName();
mTankGame = MyGUI::Gui::getInstance().createWidget<MyGUI::Button>("Button", MyGUI::IntCoord(20, 150, 120, 30), MyGUI::Align::Default, "Back");
mTankGame->setFontName(fontname);
mTankGame->setCaption(L"#ff0000坦克游戏");
mTankGame->setTextShadow(true);



Whenever you change SceneManager you also need to tell MyGUI about that. Something like this:
(MyGUI::OgrePlatform*)mPlatform->getRenderManagerPtr()->setSceneManager(newSceneManager);

o ~~~~~~~~~
thank you.