Thanks, I'm glad it's useful for you.
As some of you already noticed, script sometimes causes turning more than one page. I've added delay command so it acts more like original next page button. You can find fixed script as well as version without orientation check in first post.
@jeromedevine, yes it is possible to map spacebar key, but it will also bring search box everytime you press it, because my script isn't blocking original funcionality of keys.