UiApplication.getUiApplication().popScreen() not working

I got this message: when i pop开发者_如何学编程 the Screen

FocusHistory: Focus lost; App AppName; Component net.rim.device.api.ui.component.ButtonField

UiApplication.getUiApplication().popScreen() is deprecated .... try using

UiApplication.getUiApplication().popScreen(Screen _screen);

1) UiApplication.getUiApplication().popScreen(this);

2) UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());