Check a value in array

Hi all.

In _PostgreSQL 7.3.5_, I have to check if a value is in an array.

I've got an array of dates (date[]) in a table and I would like to
perform queries like:

SELECT * FROM table WHERE date IN dates_array;

I've tried using array_contains_date (contrib/array_iterator.sql)
function unsuccessfully:

SELECT array_contains_date(dates_array, date);

WARNING:  plpgsql: ERROR during compile of array_contains_date near line
5. ERROR:  missing .. at end of SQL expression

Anyone can help me?
Thanks,
Marco