function blockError(){return true;}
window.onerror = blockError;

if(window.addEventListener) {
window.addEventListener("load", loadEvents, true);
}
else if(window.attachEvent) {
window.attachEvent("onload", loadEvents);
}

var currentimage;
var linkslist = Array();
linkslist[0] = Array('index.htm','8n');
linkslist[1] = Array('Tree-Ring%20Dating.htm','2n');
linkslist[2] = Array('Archaeology.htm','3n');
linkslist[3] = Array('Buildings','4n');
linkslist[4] = Array('Live%20Tree%20Analysis.htm','1n');
linkslist[5] = Array('Research.htm','5n');
linkslist[6] = Array('Services.htm','6n');
linkslist[7] = Array('Tree-Ring%20Links.htm','6n');
linkslist[8] = Array('Contact.htm','10n');

function loadEvents() {
currentimage = document.getElementById('topimage').src;
	if(!currentimage) return;
var menublock = document.getElementById('linkstable');
menublock.onmouseout = resetImage;
var links = menublock.getElementsByTagName('a');
var imageload = Array();
var check = 0;

	for(var k = 0; k < linkslist.length; k++) {
	imageload[k] = new Image();
	imageload[k].src = 'picts/'+linkslist[1]+'.jpg';
	}
	
	for(var i = 0; i < links.length;i++) {

		if(links[i].className.indexOf('current') != -1) links[i].onmouseover = resetImage2;
		else {
			for(var j = 0; j < linkslist.length; j++) {
				if(links[i].href.indexOf(linkslist[j][0]) != -1) {
				links[i].onmouseover = changeImage;
				links[i].setAttribute('imageref',linkslist[j][1]);
				check = 1;
				break;
				}
			}
			if(!check) links[i].onmouseover = resetImage2;
			else check = 0;
		}
	}
}

function changeImage() {
var imgref = this.getAttribute('imageref');
document.getElementById('topimage').src = 'picts/'+imgref+'.jpg';	
}

function resetImage(e) {
	if (!e) var e = window.event;
var relTarg = e.relatedTarget || e.toElement;
	if(relTarg.nodeName && relTarg.nodeName == 'A') return;
document.getElementById('topimage').src = currentimage;
}

function resetImage2() {
document.getElementById('topimage').src = currentimage;
}