How Do You Know When You're Done With Something?

When you run out of time, basically. And somebody takes it away to ran ido. But sometimes it's like i don't have any more ideas. I know something isn't working in here, but i'm tired and i can't see it. So then i'll give it to people with to say. They think something completely different than what i do. That's a really big thing that all professional writers are going for - this is a movie. It needs tons of work, but it's a movie.