Complicated Query - Select Based On Value

SQL2K on W2Kserver

I need some help revamping a rather complicated query. I've given the
table and existing query information below. (FYI, changing the
database structure is right out.)

The current query lists addresses with two particular types
('MN30D843J2', 'SC93JDL39D'). I need to change this to (1) check each
contact for address type 'AM39DK3KD9' and then (2) if the contact has
type 'AM39DK3KD9' select types ('AM39DK3KD9', 'ASKD943KDI') OR if the
contact does not have that type then select types ('MN30D843J2',
'SC93JDL39D'). (Context - the current query selects two standard
address types "Main" and "Secondary"; we've added new data and now have
types "Alternate Main" and "Alternate Secondary". If the Contact has
Alternate addresses, I need to select those; if not, I need to select
the standard addresses. There are other address types in use, so I
must specify which types to select.)

Can anyone point me in the right direction?

Thanks very much! jamileh

CREATE TABLE [CONTACTS] (
[CONTACT_X] [char] (10),
[LONGNAME] [char] (75),
[ACTIVE] [bit])

CREATE TABLE [CONTACTADDRESSES] (
[CONTACT_X] [char] (10),
[ADDRESS_X] [char] (10),
[ADDRESSTYPE_REFX] [char] (10),
[ACTIVE] [bit])

CREATE TABLE [ADDRESSES] (
[ADDRESS_X] [char] (10),
[ADDRESSLINE1] [char] (60),
[ADDRESSLINE2] [char] (60),
[CITY] [char] (20),
[STATE] [char] (2),
[ZIPCODE] [char] (11),
[PHONE] [char] (10))

CREATE TABLE [REFERENCETABLE] (
[REFERENCETABLE_X] [char] (10),
[ADDRESS_X] [char] (10),
[DESCRIPTION] [char] (60))

CREATE TABLE [MASTERTABLE] (
[CONTACT_X] [char] (10),
[RECORDTYPE] [char] (1),
[ACTIVE] [bit])

CREATE VIEW vw_CONTACTInfo_ListLoc
AS
SELECT CONTACTS.CONTACT_X, CONTACTS.LONGNAME,
CONTACTADDRESSES.ADDRESSTYPE_REFX,
Type_REFERENCETABLE.DESCRIPTION AS Type_DESCRIPTION,
CONTACTADDRESSES.ADDRESS_X, ADDRESSES.ADDRESSLINE1,
ADDRESSES.ADDRESSLINE2, ADDRESSES.CITY, ADDRESSES.STATE,
ADDRESSES.ZIPCODE, ADDRESSES.PHONE
FROM CONTACTS INNER JOIN CONTACTADDRESSES ON
CONTACTS.CONTACT_X = CONTACTADDRESSES.CONTACT_X INNER JOIN
ADDRESSES ON CONTACTADDRESSES.ADDRESS_X =
ADDRESSES.ADDRESS_X
INNER JOIN REFERENCETABLE Type_REFERENCETABLE ON
CONTACTADDRESSES.ADDRESSTYPE_REFX =
Type_REFERENCETABLE.REFERENCETABLE_X
WHERE (CONTACTS.ACTIVE = 1) AND (CONTACTADDRESSES.ADDRESSTYPE_REFX
IN
('MN30D843J2', 'SC93JDL39D') AND (CONTACTADDRESSES.ACTIVE =
1)) AND
(CONTACTS.CONTACT_X IN
(SELECT CONTACT_X FROM MASTERTABLE WHERE
ACTIVE = 1 AND RECORDTYPE = 'E'))