Brown hamburger and onion, drain. Combine brown sugar, vinegar, mustard, worcestershire sauce, salt, pepper, tomato juice, ketchup and water-pour over browned hamburger. Bring to a boil, then simmer over medium low heat. While simmering, add small amounts of quick cooking oatmeal to hamburger mixture to thicken up sauce-sprinkle slowly in parts. Serve over buns.