Combine Brown Sugar, Butter, White Corn Syrup & Salt in a microwave dish.  Bring ingredients to boil in microwave and cook on full power for 2 minutes.  Remove from microwave and stir in Baking Soda.  Put popped corn into a brown paper bag & pour mixture over pop corn in bag and shake well.  Put bag with pop corn into the microwave & cook on high for 1 1/2 minutes, take out and shake or stir.  Put bag back into the microwave & cook on high for another 1 1/2 minutes, take out and shake or stir.   Then pour carmel corn onto a cookie sheet to cool & eat!