Melt butter or margarine in heavy saucepan. Saute celery and onion until softened. Blend in the flour and cook and stir until bubbly. Add salt and milk; cook and stir until thickened. Stir in parsley. Arrange eggs in a greased 1-1/2-quart casserole and pour sauce over. Toss together the melted butter and bread cubes and place on top of casserole. Bake at 400°F. for 15 minutes.