CREATE TABLE table_78404 ("Date" TEXT, "Venue" TEXT, "Score" TEXT, "Result" TEXT, "Competition" TEXT)

What was the name of the competition that took place on may 31, 2008?
SELECT "Competition" FROM table_78404 WHERE "Date" = 'may 31, 2008'
SELECT "Competition" FROM "table_78404" WHERE "Date" = 'may 31, 2008'