Homemade Soft Caramels

1 c light corn syrup
2 c packed light brown sugar
1 can(s) sweetened condensed milk
1/2 lb (2 cups)** butter

 Combine corn syrup, brown sugar, milk and butter in a saucepan. 
    Bring to a boil over medium heat. 
    Cook for 20 Minutes* stirring constantly. 
    Pour into buttered oblong pan.
    Cut into squares when cool.