postgreSQL and bytea / image

Hi, In my PHP page i upload pictures into database. For that i wrote a simple function which control which user is logged and will upload his picture. here is the function : CREATE OR REPLACE FUNCTION sp_a_006("login" character varying, photo bytea)

RETURNS boolean AS $BODY$ DECLARE

    my_id    INTEGER :=0;

BEGIN

    select into my_id
        account_id from accounts where account_login = $1;
    IF (my_id != 0) THEN
        UPDATE users
        SET user_photo = $2
        WHERE user_account_id = my_id;
        RETURN (TRUE);
    ELSE
        RETURN (FALSE);
    end if;

END;

when i call this function in PHP, i do the following : $my_query = "select * from immense.sp_a_006

('".$_SESSION["username"]."','{$escaped}')"; $res_pic = pg_query(my_query);

where $escaped = pg_escape_bytea($data); this inserts the picture only if i add E in front of '{$escaped}' and becomes E'{$escaped}'). why ? on another website i do not use function but a simple SQL query as following and it works : pg_query("INSERT INTO photo (photo_id,document_orientation_id, photo_date,

photo_image)

                                                  VALUES

(nextval('photo_photo_id_seq'),".$orientation_id[0].",NOW(), '{$escaped}')");

thanks a lot, -- Alain ------------------------------------ Windows XP SP2 PostgreSQL 8.1.4 Apache 2.0.58 PHP 5