Heat oven to 375°F. Beat margarine and sugars until creamy. Add eggs, milk and vanilla; beat well. Add combined flour, baking soda and salt; mix well. Stir in oats, chocolate chips and nuts; mix well. Press dough onto bottom of ungreased 13 x 9-inch baking pan. Bake 30 to 35 minutes or until light golden brown. Cool completely; cut into bars. Store tightly covered.