inserting to a multi-table view

Hi,

This feels like a very basic question but I cannot figure it out.
Suppose I have two tables and a view that combines their data:

CREATE TABLE person
 (person_id SERIAL PRIMARY KEY,
  ...);

CREATE TABLE student
 (student_id SERIAL PRIMARY KEY,
  person_id INTEGER REFERENCES person,
  ...)

CREATE VIEW studentinfo AS
  SELECT * FROM person JOIN student USING person_id;

I want to be able to do INSERTs on "studentinfo" and have rows created
in both "person" and "student".  This requires first inserting into
"person", capturing the "person_id" of the resulting row, and using it
to insert into "student".  This seems as though it must be a common
situation.

I am happy to use either rules or triggers, but I can't figure
out how to do it with either.  I can write a rule that does two
INSERTs but I don't know how to capture the id resulting from the
first insert and put it into the second.  I can write a trigger
function that does the right thing, with 'INSERT ... RETURNING
person_id INTO ...', but Postgres will not let me add an INSERT
trigger to a view; it says 'ERROR: "studentinfo" is not a table'.

The Postgres manual:
  http://www.postgresql.org/docs/8.3/static/rules-triggers.html
says "a trigger that is fired on INSERT on a view can do the same as
a rule: put the data somewhere else and suppress the insert in the
view."  So what do I need to do to make an INSERT trigger on a view?

Thanks,
Mike