How to use Screen.Jump?

I'm sure this is something very simple, but I can't seem to get Screen.Jump to work. The Help File syntax is:

Screen.Jump (string ScreenName)

I assume that by ScreenName they mean the Screen ID in the designer? In any case, I want to jump to the PreLoad section of the current screen. I expect that when calling Screen.Jump it will go to the Preload section of the target screen? But the jump does not seem to be happening.

Am I missing something?

Thanks.