1. Combine the corn syrup, brown sugar and butter into a saucepan and simmer gently until the sugar melts. Pour this mixture into the bottom of a greased 9x12 inch casserole dish.
2. Place the bread slices over the sugar mixture.
3. In a separate bowl beat together milk, eggs, vanilla and salt. Pour the egg mixture over bread.
4. Cover the dish and let stand overnight in the refrigerator.
5. The next morning, preheat over to 350F. Uncover the casserole dish and bake for approximately 45 minutes.