In a large bowl, beat together butter and cream cheese. Stir in the kernel corn, cream-style corn, chilies and onion; mix well. Pour into a greased 8-in. Square baking dish. Bake, uncovered, at 350! for 15 minutes. Remove from oven; stir in half of the fried onions. Sprinkle remaining fried onions on top. Bake 15 minutes longer. Yield: 8-10 servings.