Who was the home team on September 20, 1998 at Spartan Stadium?
CREATE TABLE "mls_regular_season" (
  "date" text,
  "home_team" text,
  "score" text,
  "away_team" text,
  "venue" text
);
SELECT "home_team" FROM "mls_regular_season" WHERE "venue"='spartan stadium' AND "date"='september 20, 1998';