KJV:
I said in mine heart, Go to now, I will prove thee with mirth, therefore enjoy pleasure: and, behold, this also is vanity.
NKJV:
I said in my heart, 'Come now, I will test you with mirth; therefore enjoy pleasure'; but surely, this also was vanity.
NIV:
I said to myself, 'Come now, I will test you with pleasure to find out what is good.' But that also proved to be meaningless.