One Bowl Chocolate Fudge

1 package 8 squares semisweet chocolate
2/3 cups Sweetened condensed milk
1 teaspoon Vanilla
1/8 teaspoon Salt
1 cup Chopped walnuts

Microwave chocolate and milk in 1 1/2 quart microwavable bowl on high for 2 minutes, stirring after 1 minute. Stir until chocolate is completely melted and smooth. Stir in vanilla, salt and walnuts. Spread in greased 8 x 4 or 9 x 5 inch loaf pan. Refrigerate until firm, about 2 hours; cut into small squares.