Thunk.com Code-breaking Challenge

OK, technically we will be dealing with a "cipher" rather than a code here, and our 4th and 5th graders should be able to tell you the precise difference. Here is what you need to do:

1. Select the enciphered message below.
2. Copy it.
3. Go to the website http://www.thunk.com
4. Paste the message into the message box and click Unscramble.
5. Follow the directions in the deciphered message and that is how I'll know you've cracked it!

Panrc jfax! Vo lfd ran anruvep cqvb lfd qrin untvgqnanu cqn znbbrpn. Efj unycn cqvb znbbrpn reu clgn ve lfda erzn, btqffy reu parun reu cqne tyvtx "Btarzsyn." Tfgl lfda btarzsynu znbbrpn vecf r tfzznec fe cqn syfp gfbc. Cqrc'b qfj V'yy xefj lfd uvu vc!(thunk.com)