Mdx, Avg with crossjoin and calculated members

Hi mates

WITH
MEMBER [MEASURES].X AS AVG([MEASURES].[ITEM VALUE])
MEMBER MEASURES.PARENTID AS
[DEPARTMENT].[DEPARTMENTS].CURRENTMEMBER.PARENT.NAME MEMBER
MEASURES.CHILDRENID AS
GENERATE(DESCENDANTS([DEPARTMENT].[DEPARTMENTS].CURRENTMEMBER),
[DEPARTMENT].[DEPARTMENTS].CURRENTMEMBER.NAME, " - ")
MEMBER MEASURES.CHILDRENNAME AS
GENERATE(DESCENDANTS([DEPARTMENT].[DEPARTMENT].CURRENTMEMBER),
[DEPARTMENT].[DEPARTMENT].CURRENTMEMBER.NAME, " - ")
SELECT
CROSSJOIN([TIME].YEAR.&[2006],
[TIME].[DATEHIER].[MONTH].MEMBERS,
DESCENDANTS([DEPARTMENT].[2],
[DEPARTMENT].[DEPARTMENTS].CURRENTMEMBER, SELF_AND_BEFORE)) ON ROWS ,
{(MEASURES.PARENTID), (MEASURES.CHILDRENID),
(MEASURES.CHILDRENNAME), [MEASURES].X} ON COLUMNS
FROM OLAPDEV
WHERE ([ITEM].[78])

this MDX Query returns the following result
Year
Month
Department
Department ParentId
Department ChildrenIds
Department ChildrenNames
ItemValue (Measure Value)

This returns sum of Item value for each month,year and deparmemnt.

But I need Avg of Item Values for each month, year and department

please help me


thanks

anand