Place 1 cube (½ cup) butter or margarine into a 13x9x2 pan. Melt in a moderate oven. Sprinkle 1 cup graham cracker crumbs on butter. I kind of mix the butter and crumbs and press into the pan. Add 1 cup shredded coconut, then 12 oz. semi sweet chocolate chips. Do not stir. Pour 1 can sweetened condensed milk on top Add 1 cup of chopped walnuts on top. Do not stir. Bake at 350 degrees for 30 minutes. Cool completely. Cut into bars.