BEGIN
  DECLARE planid,  min_sec, incr_sec INT;
  DECLARE price, conn_cost, per_min FLOAT;

  SELECT id_plans
               INTO planid
               FROM Customers
               WHERE Customers.accountcode = accountcode;
  SELECT sell_conn_cost, sell_min_sec, sell_incr_sec, sell_per_min
               INTO  conn_cost, min_sec, incr_sec, per_min
               FROM Tariffs
               WHERE Tariffs.id_plans = planid AND Tariffs.id_destinations = destination_id;

  IF seconds = 0
  THEN RETURN 0;
  END iF;
  IF seconds < min_sec
  THEN SET seconds = min_sec;
  SET price = conn_cost + ((per_min*incr_sec/60) * ((seconds DIV incr_sec)));
  RETURN price;
  END IF;
  SET price = conn_cost + ((per_min*incr_sec/60) * ((seconds DIV incr_sec)));
  RETURN price;
END