Insert rule and seqences

Hi ...

I would be very happy if someone could please give me a hint on this
subject, as PosgreSQL confuses me on this matter.

I have been trying to make a simple rule upon a insert statement to a
table that refers to a sequence, but I keep getting this strange error
every time i use this rule, saying :

ERROR: entity_seq.currval is not yet defined in this session

The idea is that I have two tables I like to bind on a insert to one of
them, like this :

CREATE SEQUENCE entity_seq;

CREATE TABLE A (
id INTEGER DEFAULT nextval( 'entity_seq' ),
name TEXT
);

CREATE TABLE B (
name TEXT,
a_ref INTEGER NOT NULL -- REFERENCES A( id )
);

CREATE RULE insert_on_a
AS ON INSERT
TO A (
INSERT INTO B name, a_ref VALUES( name, currval( 'entity_seq'
));
);

Is this all wrong, or is the another way to get the new 'id' value from
the A table ?

Im looking forward to be enlightened :-)

/BL