Cracker Dressing

1/2 cup chopped celery
1/2 cup chopped onion
2 tablespoons butter or margarine
1 egg
2/3 cup milk
1 tablespoon minced fresh parsley
1/2 teaspoon rubbed sage
1/4 teaspoon dried thyme
1/4 teaspoon salt
Dash of pepper
2 cups coarsely-crushed saltines (about 27 crackers)

In a skillet over medium heat, saut