CREATE TABLE table_71974 ("Date" CLOB, "Tournament" CLOB, "Surface" CLOB, "Opponent in the final" CLOB, "Score" CLOB)

Name the surface for 12 september 2006
SELECT "Surface" FROM table_71974 WHERE "Date" = '12 september 2006'
SELECT "Surface" FROM "table_71974" WHERE "Date" = '12 september 2006'