Pasta with Yogurt Sauce

8 ounces green noodles
2 (8 ounce) cartons plain yogurt (at room temperature)
1 cup small curd cottage cheese (at room temperature)
1/2 cup coarsely chopped scallions
1/2 to 1 clove garlic, minced
2 tablespoons fresh dill weed
1 teaspoon salt
1 tablespoon minced fresh oregano or
    1 teaspoon dried oregano
2 tablespoons butter

Cook noodles according to direction on package, drain and keep hot.

Combine yogurt, cottage cheese, onion, garlic and seasonings. Pur