How many viewers did the episode written by Warren Lieberstein & Halsted Sullivan have?
CREATE TABLE "table1_17482534_1" (
  "no_in_series" text,
  "no_in_season" text,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_millions" text
);
SELECT "u_s_viewers_millions" FROM "table1_17482534_1" WHERE "written_by"='Warren Lieberstein & Halsted Sullivan';