CREATE TABLE table_22529 ("Series #" TEXT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Prod. code" FLOAT)

Who wrote the episode originally aired on September 29, 1999?
SELECT "Written by" FROM table_22529 WHERE "Original air date" = 'September 29, 1999'
SELECT "Written by" FROM "table_22529" WHERE "Original air date" = 'September 29, 1999'