Jquery, on a big HTML with scroll, how to capture only the visible part of the HTML?

I have a big html renderized on the browser, and I need to capture only the visible part I'm seeing, if I scrool down I need to be able to capture only from the visible (portview) top until the end of the visible part. In another words, print the portview html elements. the print part is OK, but how to capture i couldn't capture the HTML elements. Any suggestion? Bes开发者_StackOverflowt regards. Ronaldo

I don't think it's really possible. At least, not outside a Chrome extension. Here's a presentation that demos the feature.