Peanut Butter Fudge

1 cup peanut butter
2 cups sugar
2/3 cup milk
1 tsp. vanilla
1 stick maragine

Melt margarine, add sugar and milk. Bring to a boil, reduce heat to medium high, cook for about 5 minutes longer (after boiling starts) stirring constantly. Remove from heat, add peanut butter and vanilla. Mix well, pour into pan, let cool, cut into squares.