Heat oven to 375 F. Beat together margarine and sugars until light and fluffy. Beat in egg and vanilla. Combine flour, baking soda and salt; add to margarine mixture, mixing well. Stir in oats, chocolate pieces and nuts. Drop by rounded teaspoonfuls onto ungreased cookie sheet. Bake 9 to 11 minutes. Cool 1 minute on cookie sheet; remove to wire rack. Store in tightly covered container. NUTRITIONAL ANALYSIS per cookie: calories 102 carbohydrates 11 g protein 1 g fat 6 g calcium 8 mg sodium 55 mg cholesterol 4 mg dietary fiber 0 g