CREATE OR REPLACE FUNCTION public.f_test_upd(
    fkey integer,
    t1 text DEFAULT NULL::text,
    t2 text DEFAULT NULL::text,
    t3 text DEFAULT 'inuse'::text,
    i4 integer DEFAULT NULL::integer)
  RETURNS integer AS
$BODY$
begin
UPDATE public.vl
   SET vlname=t1, vldesc=t2, tstatus=t3, volt=i4
 WHERE id=fkey;
return fkey;
end;

$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

CREATE OR REPLACE FUNCTION public.f_test(t1 text DEFAULT NULL::text)
  RETURNS integer AS
$BODY$

declare fkey integer;
declare iout integer;
begin
fkey = (SELECT id + 1 FROM vl ORDER BY id desc LIMIT 1);
if fkey is null then fkey = 1; 
end if;


INSERT INTO vl(id)
    VALUES (fkey); 
EXECUTE 'PERFORM f_test_upd(' || fkey || ',' || t1 || ');' INTO iout;
  
return fkey;
end;

$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

ERROR:  syntax error at or near "PERFORM"
LINE 1: PERFORM f_test_upd(10,arg1, arg2, agr3, 4);