usesUnderlying =
sandwich.lowestAnimation.usesUnderlyingValue();
anim.isDirty = false;
}
if (usesUnderlying && !sandwich.listenerRegistered) {
target.addTargetListener(null, propertyName, true,
targetListener);
sandwich.listenerRegistered = true;
} else if (!usesUnderlying && sandwich.listenerRegistered) {
target.removeTargetListener(null, propertyName, true,
targetListener);