Answer
Dogs can be trained to use a certain area set aside for elimination. They're less fussy than cats about what materials you use to absorb the waste, so you could put old newspapers, paper litter, clay, or another absorbent material in the bottom of the pan. No matter what material you decide to use, use it consistently. At first, you may want to leave the litter a little dirty, because dogs tend to go back to a place where they have gone before. For the same reason, clean the carpet whenever your dog has an accident, to be sure she doesn't return to the same spot.

Most of all, be patient and consistent. Develop a schedule of feeding, playing, walking, and sleeping, which will keep your dog on an elimination schedule as well. Learn the times when she will generally have to go: after eating, after waking up and, for puppies, about every 20-30 minutes when they are awake and playing. Watch for the cues your dog gives before urinating, like sniffing and circling, and place her in the pan when you see her getting ready to go. Praise her when she uses the pan.

Different dogs learn at different rates, so it may take a few days of accidents before your pet learns to use the pan. Eventually, though, with gentle persistence, she can learn to use the litter box consistently. Remember, though, the pan is not meant to replace trips outside, but to supplement them. Your dog still needs to go outside for exercise and fresh air every day.