CREATE TABLE table_60477 ("Edition" CLOB, "Round" CLOB, "Date" CLOB, "Surface" CLOB, "Opponent" CLOB, "Result" CLOB)

Who was the opponent on april 24, 1999?
SELECT "Opponent" FROM table_60477 WHERE "Date" = 'april 24, 1999'
SELECT "Opponent" FROM "table_60477" WHERE "Date" = 'april 24, 1999'