Creamy Peanut Butter Fudge

2 cups sugar
1 cup milk
1/2 teaspoon salt
1 tablespoon butter
1 teaspoon vanilla
1/2 cup peanut butter
1/2 cups nuts (optional)

Butter the sides of a 2 quart saucepan. In it combine sugar, milk, salt. Heat over medium heat , stirring constantly until sugar dissolves, and mix comes to a boil. Cook to a soft ball stage (238 degrees)stir only if neccessary. Remove from heat and add peanut butter, nuts if desired, and butter. Add vanilla and beat well--pour quickly into buttered dish to cool.