To activate the menu system, the user presses the menu button (the right mouse button). This displays the menu bar in the screen's title area. The menu bar displays a list of topics (called menus) that have menu items associated with them (see figure). The menu bar and menu items only remain visible while the menu button is held down. figure 6-1: screen with menu bar displayed When the mouse pointer is moved onto one of the menus in the menu bar, a list of menu items appears below the menu. The user can move the pointer within the list of menu items while holding down the menu button. A menu item will highlight when the pointer is over it and, if the item has a sub-item list, that list will be displayed. The specific menu that is displayed belongs to the active window. Changing the active window will change the menu bar and the choices available to the user. Unlike some other systems, the Amiga has no "standard menu" that appears in every menu bar. In fact, a window need not have any menus at all, thus holding down the mouse menu button does not guarantee the appearance of a menu bar. Although there is no "standard menu", Amiga, Inc. does have a well-defined set of standards for menu design. These standards are covered in The Amiga User Interface Style Guide (also from Addison-Wesley). selecting menu items menu item imagery