PL/pgSQL help

I'm a bit new to plpgsql, so this may be an easy question,

I've got a function (see below) that inserts into 3 different
tables.  Each table has a SERIAL type for it's primary key.

Question 1:
   I want to group all 3 inserts as a transacation.

   but when I put BEGIN WORK and COMMIT I get the error (at run time):
NOTICE:  plpgsql: ERROR during compile of easy_add near line 21
ERROR:  parse error at or near ""

   this is the line with COMMIT on it;

   What am i doing wrong?
   Also, do I also need to specify a ROLLBACK if any of the inserts fail?

Question 2:
   is there a way to get the value of the newly assigned primary key
   after an insert?  (rather then following the insert with a select)

   e.g. (this would be nice if it worked (networkID is the PKey))
   INSERT into Network (parentID, networkName) values (pid, mname);
   netid := new.networkID;


thanks for your time!!!



DROP FUNCTION easy_add(int4, text, inet);
CREATE FUNCTION easy_add(int4, text, inet)
RETURNS int4 AS '
DECLARE
   pid   alias for $1;
   mname alias for $2;
   ip    alias for $3;
   netid int4;
   ipid  int4;
   rec   record;
BEGIN
   -- BEGIN WORK;
   INSERT into Network (parentID, networkName) values (pid, mname);
   SELECT into rec * FROM Network WHERE networkName = mname;
   netid := rec.networkID;
   INSERT into AddressSpace (networkID, address) values (netid, ip);
   SELECT into rec * FROM AddressSpace WHERE networkID = netid AND address =
ip;
   ipid := rec.addressID;
   INSERT into NetworkAddress(networkID, addressID) values (netid, ipid);
   -- COMMIT WORK;
   return 1;
END;
' LANGUAGE 'plpgsql';