Grease one 8-inch square baking pan.

In 2-quart saucepan combine sugar, milk, cocoa, corn syrup and salt.

Cook over medium heat, stirring constantly until sugar is dissolved.

Cook, stirring occasionally, to 234°F on candy thermometer (or until small amount of mixture, dropped into very cold water, forms a soft ball which flattens when removed from water).

Remove from heat, add butter.

Cool mixture to 120°F without stirring (bottom of pan will be lukewarm).

Add vanilla, beat vigorously and continuously for 2 minutes with wooden spoon.

Quickly stir in nuts.

Spread mixture evenly into prepared pan.

Cool until firm.  Cut into squares.