Let's face it: when you're working on artwork in Flash, sometimes you need as much available space as possible. That means getting rid of as many extras as possible - and sometimes the timeline is one of those extras. Sure, you can shrink it down to just a small area, with only a few layers visible in the list. But when that's not enough, you can click the
Hide Timeline button. You can find this at the bottom of the timeline, to the far left and above the stage. This will make the timeline vanish, although you can easily recover it by clicking the button again.