ERROR: syntax error at or near "select" at character 9

Hi

I am using PG 8.0 on Win32, learning SQL.
I dod create a table with the following SQL:
  CREATE TABLE test (      id integer,      nev varchar(25),      datum timestamp  );

A sequence with:
  CREATE SEQUENCE "public"."test_azon_seq"      INCREMENT 1  MINVALUE 101      MAXVALUE 9223372036854775807  START 101
   CACHE 1  ;
 

A before insert trigger:
  CREATE FUNCTION test_verif() RETURNS trigger AS $test_verif$      BEGIN          NEW.id := select
nextval('test_azon_seq');         NEW.nev := nev;          NEW.datum := current_timestamp;          RETURN NEW;
END; $test_verif$ LANGUAGE plpgsql  ;
 
  CREATE TRIGGER test_verif BEFORE INSERT ON test      FOR EACH ROW EXECUTE PROCEDURE test_verif()  ;

When I issue the
  insert into "public"."test" (nev) values ('Graf László');

insert statement, it returns

"ERROR:  syntax error at or near "select" at character 9".

Why? What is wrong?

-- 
László Graf