In a small bowl, combine the salt and garlic. Stir in yogurt. Cover and refrigerate. In a medium sauce pan or skillet, heat 1 1/2 inches of oil on medium heat. Meanwhile, in a small bowl, add 1 1/2 cups flour and stir in enough water to make a smooth, medium-thin batter. Add remaining flour to a separate bowl. Coat zucchini slices in flour, and then dip in batter, working in batches. Fry until golden, or about 3 minutes per side. Remove from oil and place on a paper towel to drain. Transfer yogurt mixture to a serving bowl and serve with the zucchini slices.