Mutual exclusion allows the selection of an item to cause other items to become unselected. For example, for a list of menu items describing the available sizes for a font, the selection of any size could unselect all other sizes. Use the MutualExclude variable in the MenuItem structure to specify other menu items to be excluded when the user selects an item. Exclusion also depends upon the CHECKED and CHECKIT flags of the MenuItem, as explained below. * If CHECKED is not set, then this item is available to be selected. If the user selects this item, the CHECKED flag is set and the checkmark will be drawn to the left of the item. * If the item selected has bits set in the MutualExclude field, the CHECKED flag is examined in the excluded items. If any item is currently CHECKED, its checkmark is erased, and its CHECKED flag is cleared. * Mutual exclusion pertains only to items that have the CHECKIT flag set. Attempting to exclude items that do not have the CHECKIT flag set has no effect. Keep track of deselected items. ------------------------------- It is up to the program to track internally which excluded items have been deselected. See the "Enabling and Disabling Menus and Menu Items" section below for more information. In the MutualExclude field, bit 0 refers to the first item in the item list, bit 1 to the second, bit 2 to the third, and so on. In the text style example described above, selecting plain excludes any other style. The MutualExclude fields of the four items would look like this: _____________________ | | | Plain 0xFFFE | | Bold 0x0001 | | Italic 0x0001 | | Underline 0x0001 | |_____________________| "Plain" is the first item on the list. It excludes all items except the first one. All of the other items exclude only the first item, so that bold, underlined text may be selected, while bold, plain text may not.