Passing array to PL/SQL and looping

All,

I'm a newbie to PL/SQL and need help badly. I'm trying to pass my array of
id's to the function and then loop through until the array is empty. I know
there must be atleast five things I'm doing wrong.

Please help!

Cheers,
-p

Call to Procedure and Array:

$myArray = array(15, 6, 23);
select generateInvoice($myArray);

Procedure:

CREATE FUNCTION generateInvoice (VARRAY) RETURNS int4 AS '

DECLARE
-- local variables
temppk INT4;
v_pids := $1;
v_count BINARY_INTEGER := 1;
id INT4;

BEGIN
SELECT INTO temppk nextval(''t_task_task_id_seq'');

LOOP
IF v_pids.EXISTS(v_count) THEN

id := v_pids.NEXT(v_count);

UPDATE t_project SET task_id=temppk WHERE project_id=id;

v_count := v_count + 1;

ELSE
EXIT;
END IF;
END LOOP;

-- Everything has passed, return id as pk
RETURN temppk;
END;
' LANGUAGE 'plpgsql';