tetris for classic webtv box

I have finally fixed the tetris game at http://www.kielack.com/games/tetris.php so that it is even working in a classic webtv box.
Although I had written it already in a very basic javascript it did not run on a classic webtv box.
It ran fine in a emulator but that covers only the newer web boxes.
Fortunately I found a user, who could test it for me.
It took me quite some time until I figured that the classic box did not support
do { } while
but only
while { }
after a minor change in the logic the games runs now as originally intended.