Classic Magic Cookie Bars

Why I Love This Recipe
I found this recipe on Bake & Destroy, but I'm pretty sure this is a common recipe, I know I've made these before. : )
Ingredients You'll Need
1/2 cup butter or margarine
1 1/2 cups graham cracker crumbs
1 (14 ounce) can sweetened condensed milk
1 (12 ounce) package semisweet chocolate chips*
1 1/3 cups flaked coconut
1 cup chopped nuts (walnuts, usually, but whatever you like)
Directions
Then you:
1. Preheat oven to 350 degrees F (325 degrees for glass dish). In 13×9-inch baking pan, melt margarine in oven. Sprinkle crumbs over butter; pour condensed milk evenly over crumbs. Layer evenly with remaining ingredients; press down firmly.
2. Bake 25 minutes or until lightly browned. Cool. Chill if desired. Cut into bars.
*For an even more fun bar, use 1 cup chocolate chips, 1 cup flavored chips such as butterscotch or peanut butter chips.