Toll House Pan Cookies

2 1/4 cups unsifted flour
1 teaspoon soda 
1 teaspoon salt
1 cup softened butter 
3/4 cup sugar
3/4 cup brown sugar
1 teaspoon vanilla 
2 eggs
1 (12 ounce) package semisweet chocolate chips 
1 cup chopped nuts

Preheat oven to 375 degrees. In small bowl combine flour, soda, and salt, set aside. In large bowl combine butter,  sugar, brown sugar, and vanilla. Beat until creamy. Beat in eggs. Gradually add flour mixture; mix well. Stir in chocolate chips and nuts. Spread into greased 15 x 10 x 1 inch baking pan. Bake for 20 minutes.  Cool, cut into 2 inch squares. Makes 36 squares.