QUERY IIf Statements In Criteria

:confused:
Hi I need help inserting IIF statements as criterias in my query.

Here's the query I have created from a table called XML_EXPORT which consists of a list of ORGANIZATIONS with various fields. What I'm trying to do is display:
-the name of the EXEC_NAME_1 (primary executive's name)
-the ADDRESS
-the CITY
-the POSTAL_CODE
-the PROVINCE
-the PUBLICATION
-the ORG_LEVEL_1 (the organization's main name)
-the ORG_LEVEL_2 (the organization's departments 2 to 5)
-the ORG_LEVEL_3
-the ORG_LEVEL_4
-the ORG_LEVEL_5

Now not every record contains data in ORG_LEVEL_2 to ORG_LEVEL_5 so we want to display only ORG_LEVEL_1 and the last ORG_LEVEL that is not blank.

i.e. If a record has ORG_LEVEL_4 and ORG_LEVEL_5 blank then we want to only display: ORG_LEVEL_1 and ORG_LEVEL_3 (even though there is something in ORG_LEVEL_2)

Here's my query:

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SELECT XML_EXPORT.EXEC_NAME_1, XML_EXPORT.ADDRESS, XML_EXPORT.CITY, XML_EXPORT.POSTAL_CODE, XML_EXPORT.PROVINCE, XML_EXPORT.PUBLICATION, XML_EXPORT.ORG_LEVEL_1, XML_EXPORT.ORG_LEVEL_2, XML_EXPORT.ORG_LEVEL_3, XML_EXPORT.ORG_LEVEL_4, XML_EXPORT.ORG_LEVEL_5
FROM XML_EXPORT
WHERE (((XML_EXPORT.ADDRESS) Is Not Null));
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Can anyone show me how the Iif statement syntax would be ?
Allan