Italien Pasta Bake

1 lb ground beef
1onion chopped
1 jar spaghetti sauce
3/4 c. grated parmesan cheese
8 oz. broken spaghetti or 3 c. penne pasta cooked and drained
1 pkg. grated mozzerella cheese

Brown onion and meat.  Drain.  Stir in noodles and sauce.  Add 1/2 of parmesan cheese.  Spoon into 9/13 pan.