What type of detergent should I use in my Whirlpool dishwasher?

Use only automatic dishwasher detergent, and add it just before starting a cycle. High-quality premeasured tablets and packs are recommended for improved performance, as they have been proven better than powder, liquid, or gel detergents at reducing filming on dishes. Store detergent in a tightly closed container in a cool, dry place for best results. (Page 6)