Stored Procedure to return a result set

Dear PG users,

I'm attempting to create a stored procedure which returns a result set
from the handset table to the caller.

This stored proc will eventually be called by JDBC application. I'm
using pgadmin to write and test.

No luck so far. Here's what I have......

CREATE OR REPLACE FUNCTION getunassigned(state integer)
  RETURNS SETOF macaddr AS
$BODY$BEGIN
        SELECT mac FROM handsets WHERE state=$1;
END;$BODY$
  LANGUAGE 'plpgsql' VOLATILE;
ALTER FUNCTION getunassigned(state integer) OWNER TO "IPTHSACC";

when calling it via the query tool....
IPTHsAcc=> SELECT * FROM getunassigned(1);

I get an error thus....
ERROR:  SELECT query has no destination for result data
HINT:  If you want to discard the results, use PERFORM instead.
CONTEXT:  PL/pgSQL function "getunassigned" line 2 at SQL statement

Please could somebody show me a simple example of a stored proc/func
which returns a set.

my table is....

CREATE TABLE handsets (
    mac macaddr NOT NULL,
    state smallint DEFAULT 0 NOT NULL
);


many thanks for any pointers.

Rob