<oListBox>:insItem(<nPosition>, <cText>,
        [<expValue>]) --> self

        <nPosition> is a numeric value that indicates the position at
        which the new item is inserted.

        <cText> is the item's text to display in the list.

        <expValue> is a value that is associated with the list item.  If
        omitted, the item's associated data will be NIL.

        insItem() is a method of the ListBox class that is used for inserting
        a new item to a list.  When inserting an item, an optional value may
        be included.  This enables you to associate pertinent data with the
        text displayed in the list.

        Note:  When present, the scroll bar is automatically updated to
        reflect the insertion of the new item.