Bring to a boil: cocoa, water and margarine.
In a large bowl, mix: sugar, flour and salt.
Add: Cocoa mixture, eggs, vanilla and milk with soda.
Mix well and put in greased jelly roll pan.
Bake 350º for 25-30 minutes.
Frost brownies when they come out of the oven and are still hot.
Bring margarine, cocoa and milk to a boil. Then add powdered sugar and vanilla. Beat well and frost brownies.