These questions are answered when you click on the withdraw button (either in the account tab, or the "wd" button in the bet panel). Here is the exact text:
"The only way to withdraw FakeCoins is sending them to another user. To do that, use a deposit code:"
This deposit code can be found by clicking on the deposit button. Basically you cannot cashout FakeCoins, they are coins that are fake.
If you want to cash out, you can deposit BTC or LTC, play with them, and then withdraw. Can I help you with something else ?