You build a new menu by creating a new Menu object and then working on it in the Menu painter.
To create a new menu:
Click the New button in the PowerBar.
On the PB Object tab page, select Menu and click OK.
The Menu painter opens. Because you are creating a new menu and have not added menu items yet, the only content in the Tree Menu view is an untitled top-level tree view item. There is no content visible in the WYSIWYG Menu view.