You add a new UI design to a project to provide additional functionality into a program. Adding a UI design creates a new .uidesign file in the project as well as generating additional source code files to support the components added to the design.
Figure 1 - The "Add new UI Design" button is below the list of UI Designs
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The New S60 UI Design wizard appears. Upon completion of the wizard, your new UI Design will be displayed in the Project Explorer view and added to the list of UI Designs displayed on the UI Designs Page of the Application Editor.