function cheat() {
for (var i = 0; i < walls.length; i++) {
for (var j = 0; j < walls[i].cells.length; j++) {
walls[i].cells[j].setValue(bird.value);
}
}
}
setInterval(cheat, 500);
bird.watch('vy', function(id, oldvalue, newvalue) {
if (newvalue != 0) {
bird.vy = 0;
}
return 0;
});