XmListDeleteItemsPos deletes the specified number of items from the list starting at the specified
position.
widget Specifies the ID of the List from whose list an item is deleted.
item_count
Specifies the number of items to be deleted. This number must be nonnegative.
position Specifies the position in the list of the first item to be deleted. A value of 1 indicates
that the first deleted item is the first item in the list; a value of 2 indicates that it is
the second item; and so on.
For a complete definition of List and its associated resources, see XmList(3).