group by / rand problem

[hug]

Hello,

I try this sql, but it don't work :(
Have you a solution ?

----------------------------------------------------------------------
SELECT
galleries.id_ga llerie as lid ,
(
SELECT
id_contenu
FROM
contenus
WHERE
id_gallerie=lid
ORDER BY
RAND()
LIMIT 0,1
)
as lid_contenu
FROM
galleries
WHERE
galleries.home= 1 AND
galleries.onlin e=1
------------------------------------------------------------------------------

it must response me a rand id_contenu for every id_gallerie group by.

Thanks.