Melt butter in a large sauce pan over medium heat.
Add sugar and salt to the butter and mix well.
Add corn syrup, chocolate and milk. Bring to a boil, stirring constantly.
Reduce heat to medium and cook until candy thermometer
registers 245 degrees, stirring constantly. Remove pan
from heat and add vanilla. Pour into a buttered 9x9 inch pan.
Let stand at room temperature until set. Cut into 1 inch
squares with a serrated knife. Wrap each piece in plastic wrap.
Keep in a covered container. Yield: 2 1/2 lbs.