With headers, footers, status bars, baked in UI elements... you'll probably find the total height available for your page is smaller than you think - there's also the fact that most browsers have multiple default zoom levels which means that the website is often NOT displayed pixel to pixel. Then of course, there's the fact that there are devices out there with very small displays (240x320 Android devices are not uncommon). All in all you're best off leaving the scroll function intact.