CREATE TABLE table_25902 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT)

Name the directed by for 'blue christmas
SELECT "Directed by" FROM table_25902 WHERE "Title" = 'Blue Christmas'
SELECT "Directed by" FROM "table_25902" WHERE "Title" = 'Blue Christmas'