Beat eggs until light in color. Add 1 1/2 Cup of Milk. Mix well. Slowly add the flour, sugar, and salt. Then slowly add the remaining milk. Batter should be thin. Add more butter to thin if needed. Cook over medium to medium high heat. Preheat pan, add a small amount of butter to pan, and then wipe it out with a paper towel. Add approximately 1/4 cup batter to pan, turning the pan to cover the bottom of the pan. Cook on both sides. Keep warm in oven. Butter the pan before starting each crepe.