CREATE OR REPLACE FUNCTION test1(text) returns returntype AS
$_$
DECLARE
r returntype%ROWTYPE;
roz int;
pass text;
BEGIN
 BEGIN
  SELECT  id  FROM koncowki WHERE mac = $1::macaddr limit 1 INTO roz;
 EXCEPTION
  SELECT  id,password  FROM koncowki WHERE login = $1 limit 1 INTO roz,pass;
 END;
 IF NOT FOUND
   RETURN r;
 END IF;

 IF (roz = 0)
   THEN RETURN r;
 END IF;

  r.id := roz;
  r.username := $1;
  r.attribute := 'Cleartext-Password';
  r.op := ':=';
  r.VALUE := pass;

  RETURN r;
END;
$_$ LANGUAGE 'plpgpsql'