Others
Return Policy within Applications
When Return is entered within an application, the user is taken to the next highest level.
However, if the user is already at the highest level, the following rules must be followed.
- Close the application when Return is entered in the first category screen.
- Move the focus to the first item of the first category when return is entered in other categories.
Network Error Feedback
When a service is temporarily unavailable due to network errors or service failures, a notification message is provided using a popup window as shown in Figure 8-1.
This UI is provided by the system, so doesn't need to be developed separately.

Figure 8-1. Feedback for network error