Sweet and Sour Meatloaf

1 1/2 lbs ground beef
1 cup dry bread crumbs
1 tsp salt
1/4 tsp pepper
2 eggs
1 tsp instant minced onion
1 can (15 oz) tomato sauce (divided)

Topping:
Reserved tomato sauce
2 tbsp brown sugar
2 tbsp vinegar
1/2 cup sugar
2 tsp prepared mustard

Mix together beef, bread crumbs, salt, pepper and eggs. Add onions and one half of tomato sauce. Form into a loaf in a 9 x 13 pan. Bake at 350 degrees for 50 minutes. In saucepan, combime topping ingredients and bring to a boil. Pour over meat loaf, bake 10 minutes more.