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 ('Prev');
			break;
		case 0x27:
			link = document.getElementById ('Next');
			break;
		case 0x26:
			link = document.getElementById ('Up');
			break;
		case 0x28:
			link = document.getElementById ('Down');
			break;
	}
	if (link && link.href) document.location = link.href;	
}}