document.onkeydown = NavigateThrough;

function NavigateThrough (event) {
	if (!document.getElementById) return;
	if (window.event) event = window.event;
	if (event.ctrlKey) {
		var link = null;
		switch (event.keyCode ? event.keyCode : event.which ? event.which : null) {
			case 0x25: link = document.getElementById('NextLink'); break;
			case 0x27: link = document.getElementById('PrevLink'); break;
		}
		if (link && link.innerHTML) document.location = link.innerHTML;
	}
}