Query For Percentage Of A SUM

I am trying to figure out the syntax for a query that will essentially
give me the Percentage each of my areas contributes to the Whole. I
know this can be achieved by multiple queries but I would like to keep
it intact as one single query if possible.

For Example I have the following data set--

AREA MOU
NE 1234
SO 4312
WE 12312
MW 97123
NE 1123
SO 31
WE 312
MW 971

The results I would like to see would look like

AREA MOU PERCENT
MW 98094 .83536
NE 2357 .02007
WE 12624 .10751
SO 4352 .03706

The query I came up with is--

SELECT DISTINCT Area, SUM(MOU) AS AREA_TOTAL, sum(MOU) /
(SELECT SUM(MOU) AS TOTAL_MOU
FROM [2004_NOVEMBER_COST])as
[PERCENT]
FROM [2004_NOVEMBER_COST]
GROUP BY Area


All seems to calculate with the exception of the Percent where all the
percentages are 0's.

I think I need to take the first line AREA_TOTAL and now divide by the
SUM(MOU) like this--
SELECT DISTINCT Area, SUM(MOU) AS AREA_TOTAL, AREA_TOTAL /
(SELECT SUM(MOU) AS TOTAL_MOU

but I get Invalid Column.

I essence I think it is a simple query but I am hitting a wall. Any
advice would help.

Thanks,
Ben