Browser pop up...

...does anyone know where I can get a javascript pop up with a nice transition so it either grows or fades over the page. Doesn't matter if its not free. Thanks
Its not for a website its for an interactive piece thats going to be worked on using a local hard drive, just using a browser to operate it. I'd sooner shoot myself than put a pop up on a site. Its just to display information and links to the user when clicked upon
as previously mentioned, lightbox or equiv is your best bet, I don't think there are any transition effects available for actual browser windows ... they're there or they're not ...