Thank you for the explanation, ervalvola.
But it has been a good demonstration by TradeFortress. Having that useless 1 BTC in my own Ripple wallet balance that I can't spend is far more convincing than a post containing an image of someone else's wallet.
you're welcome, i'm glad to help.
By the way, i think that a demonstration whithout the risk of loosing 100 BTC for someone would have been much much much better

EDIT: it was a SMART demonstration (besides it is quite simple if you're used to ripple); that doesn't means it is good...