As one might expect, this tag specifies the contents of the menu bar. Menus contain a menupopup tag that represents the popup view for a menu. The menu popup can contain menu items or additional menus as children, the distinction being that menus always have children, and menu items never have children. The popupanchor attribute specifies where the popup will be anchored on the menu when it pops up. The default value for menus in the menubar is bottomleft.
Possible values are bottomleft , bottomright , topright , and topleft .
Bottomleft specifies that the popup will be displayed underneath the menu and flush on the left side. For menus in menu bars, all other values but bottomleft for popupanchor are ignored because of the space constraints typical of menu bars. The popupalign attribute describes the position of the popup rather than the menu. In the File menu below, the arrow is pointing to the anchor point of the menu and the alignment point of the popup. Together, these two attributes give you expert-level control overt the positioning of menus in your application.