Granny'S Chocolate Icing - cooking recipe

Ingredients

2 c. sugar
2/3 c. milk
dash of salt
cocoa to taste
1 tsp. vinegar
1/2 stick margarine

Preparation

Mix all ingredients except margarine. Cook slowly to soft-ball stage. Remove from heat. Add 1/2 stick margarine. Stir until creamy. Spread over cake.