Jiffy Potato Casserole

This is another dish I made for Thanksgiving. I got this recipe from my Grandma. I haven't made it in so long. It is so simple to make.

1 package frozen hashbrown- thawed
1 pint sour cream
1 can cream of celery soup
1/2 cup milk
1/4 cup onion, chopped
2 cups velvetta cheese, cubbed or 1 cup each velvetta and chedder cheese
1/2 cup butter, melted
1 cup crushed corn flakes

Mix all but the butter and corn flakes together. Place in a baking dish. Mix butter and corn flakes and place on top. Bake at 350 degree's for 45 minutes to 1 hour