Which Score has an Attendance of 23 january 1999, and a Tie # of 6?
CREATE TABLE "fourth_round" (
  "tie_no" text,
  "home_team" text,
  "score" text,
  "away_team" text,
  "attendance" text
);
SELECT "score" FROM "fourth_round" WHERE "attendance"='23 january 1999' AND "tie_no"='6';