EN_ITEM_GROUP_SET_NONE_SELECTED</CODE>
 deselects any settings currently on so that the list will appear with no items selected. It takes a flag indicating whether the list should be in its indeterminate state. This message will also clear the object's modified flag. If you wish to set this flag, send the GenItemGroup a <CODE>
MSG_GEN_ITEM_GROUP_SET_MODIFIED_STATE</CODE>
 after sending this message.</P>
<P>
<CODE>
MSG_GEN_ITEM_GROUP_SET_SINGLE_SELECTION</CODE>
 sets a single selection for a GenItemGroup. An