Mobile Dialog Boxes
From Xojo Documentation
A Message Box displays a prompt for the user. Although it is a user interface control, it does not appear on the Layout so when you drag it to your Layout, it is added to the Shelf. To learn more about Message Box go to the UserGuide:Mobile Message Box topic.
A modal screen is a screen that is also displayed without being "pushed" onto the current screen. A modal screen cannot have toolbars and should not have other screens pushed onto it. You can show and close a modal screen using the MobileScreen.ShowModal method.
In this example, the Login screen is being displayed modally from the current screen: