To think that prior to 2005 there wasn’t any page up / page down functionality. After all, that’s when Microsoft filed a patent application for “Method and system for navigating paginated content in page-based increments.” To be exact, March 4, 2005 was the date of the application, and the patent was granted on Tuesday. And it’s:A method and system in a document viewer for scrolling a substantially exact increment in a document, such as one page, regardless of whether the zoom is such that some, all or one page