Preheat oven to 350°F. Place butter in a 9x9 inch baking pan and put in oven to melt butter. Remove from oven and spread butter evenly over bottom of pan. Sprinkle with graham cracker crumbs, pressing down to form a crust. Sprinkle chocolate chips over top. Pour condensed milk over and sprinkle with a layer of nuts and a layer of coconut. bake 15 minutes, or until coconut is golden. When cooled, cut into bars.