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