document.onkeydown = function keyScroll(event) {
	if (window.event) {
		event = window.event;
	}
	if (event.ctrlKey) {
		switch (event.keyCode ? event.keyCode : event.which ? event.which : null) {
			case 0x25:
				followLink("prev_page_link");
				break;
			case 0x27:
				followLink("next_page_link");
				break;
		}
	}
}

function followLink(elem_id) {
	if ((elem = document.getElementById(elem_id)) && elem.href) {
		location.href = elem.href;
	}
}