list->insert_after_tag (ul_oocbs)

	new_tag.i4.v = insert_after_tag(list.s.r, item.g.r, size.i4.v,
	                                element_tag.i4.v)

	This method inserts an element immediately after the element with the
	given tag. A tag of zero is returned if the requested tag is not found,
	and the item is not inserted into the List.
	The List class actually allocates new space in which to store
	the data item, and makes its own copy of it, so that the original
	does not need to be kept after it has been inserted into the List.

	list              a pointer to the list (structure of type List)
	item              a pointer (of any type) to the item to be stored
	size              the size of the item (in bytes)
	element_tag       the tag corresponding to the item after which the
	                  new item is to be inserted into the List

	This function returns:

	an integer tag which can be used for subsequent pseudo-random
	retrieval of the item stored in the List

	Use of this class requires the following header files:

	list.h

	Related functions:

	create_List()     the constructor for instances of the List class

	C/C++ usage:

	#include "list.h"
	List	*list;
	int	item;
	int	length;
	int	old_tag;
	int	new_tag;

	new_tag = (*list->insert_after_tag)(list,(void *) &item,
	                                    sizeof(item),old_tag);