Syntax check for functions?

Hi,

is there any chance to make a syntax check of a function/trigger before
creating it.
I just wrote my first function and trigger in Postgres an dit won't work :-(

I get the error: "fmgr_info: function 541860: cache lookup failed"

May be somebody may have a look on the function and see the error(s).

Is the use of "length(new.extid) = 0" right or do I have to ask "is null"?

Greetings,
Andreas

CREATE FUNCTION trigger_insert_custno_ext()
RETURNS opaque
AS 'BEGIN
IF length(new.extid) = 0
THEN new.extid = new.custno; -- put custno into extid column
END IF;
RETURN new;
END;'
LANGUAGE 'plpgsql';

CREATE TRIGGER trigger_custno_ext
BEFORE INSERT OR UPDATE
ON tCustomer
FOR EACH ROW
EXECUTE PROCEDURE trigger_insert_custno_ext();