Is there a jQuery plugin for closable overlays?

I need a jQuery plugin that displays an overlay at the top of the screen, for notifications.

It needs to be closable. Preferably, it's text should be updatable (without closing and opening a new one - I don't want a second animation if the overlay is already displayed when the text is updated).

It also shouldn't bounce while scrolling. Does anyone know where I could find a good one?

EDIT: To clarify, it needs to be at the top of the page, and not movable. 开发者_高级运维Like the overlays you see here on Stack Overflow.

Thanks for your help.

jBar is one. It's pretty current, and I think does what you want.