Chewy Cereal Bars

In large microwave safe bowl, combine corn syrup, brown sugar and sugar and mix well. Microwave on HIGH for 4-7 minutes until bubbling, stirring twice during cooking cycle. Remove from microwave and add peanut butter. Stir until peanut butter melts and mixture is smooth. Add cereal and stir gently but thoroughly until cereal is coated. Spread mixture into greased 13x9" pan. Using back of spoon, press mixture evenly into pan. Let cool and cut into bars.