CREATE or REPLACE FUNCTION xfer (amount integer, debit TEXT, credit TEXT) 
       RETURNS integer AS $$
  --  updated 2005 for gwb table
  DECLARE
	user TEXT;		-- local variables, 
	balance INTEGER;
BEGIN
    --  Transfer the amount from debit acct to credit account, if both exist!

        select into user current_user::char(5);		-- who called the function
    update gwb set vault = vault - amount where acct=debit::char(5);

    	-- want an exception if either user is not valid! ---------
	IF not FOUND THEN
		RAISE EXCEPTION 'Debit customer % cannot be found!', debit;
	END IF;
    update gwb set vault = vault + amount where acct=credit::char(5);
	IF not FOUND THEN
		RAISE EXCEPTION 'Credit customer % cannot be found!', credit;
	END IF;
    select vault into balance from gwb where acct=user::char(5);
	IF not FOUND THEN
		RAISE EXCEPTION 'Customer % cannot be found!', user;
	END IF;
	IF debit::char(5) = user AND credit = 'out' THEN
	   UPDATE gwb set pouch = pouch + amount where acct=user;
	   RAISE INFO 'The % sickles are in your pouch', amount;
	END IF;   
    RETURN balance;
END;
$$ LANGUAGE 'plpgsql';