Preheat the oven to 400 degrees F then take nonstick cooking spray and spray a shallow 1-quart baking dish.
Take each ear of corn and pull back the husks from each, leaving the husks attached and discard the silk.
Take husks on corn and bring back up over each ear and soak the corn in cold water for 20 minutes.
Take the salmon and place it in prepared dish skin side down, then pour 1 tablespoon lime juice over the fillets and marinate for 15 minutes at room temperature.
In a small bowl, combine the garlic with chili powder, cumin, oregano, half of salt, and the pepper in small bowl. Then, pat the salmon lightly with a paper towel and rub garlic mixture on tops and sides of salmon.
Take the corn and remove from water. Then, place each corn on one side of the oven rack and roast for 10 minutes then turn.
Take the baking dish with salmon and place on other side of oven rack, then roast for 15 minutes or until the salmon has become opaque and flakes when tested with a fork and the corn is tender.
In a small bowl, combine the margarine with cilantro, remaining 1 teaspoon lime juice, and the remaining salt. Then, remove husks from corn and brush the mixture over corn. Serve corn with salmon.