If the Open... menu item is chosen, it behaves like the New menu item with regard to saving the current composition. Then, if the user hasn't canceled, an dialog appears in which the user can select a file to open. If the user chooses a valid file, it is loaded into the composition pane. If the user cancels, the dialog disappears. If the user chooses an invalid file, an error message is displayed and the open dialog stays visible.
If the Open... menu item is chosen, it behaves like the New menu item with regard to saving the current composition. Then, if the user hasn't canceled, an dialog appears in which the user can select a file to open. If the user chooses a valid file, it is loaded into the composition pane. If the user cancels, the dialog disappears. If the user chooses an invalid file, an error message is displayed and the open dialog stays visible.