function overlayShow() {
	document.getElementById('dialog').style.display = 'block';
	document.getElementById('overlay').style.display = 'block';
}

function overlayHide() {
	document.getElementById('dialog').style.display = 'none';
	document.getElementById('overlay').style.display = 'none';
}

function setSelection(id) {
	var nav = document.getElementById(id);
	if(nav) {
		var lis = nav.getElementsByTagName("li");
		var pageURL = location.href;
	
		for(var i = 0; i<lis.length; i++ ) {
			var linkURL = lis[i].getElementsByTagName("a")[0].href;
			if(pageURL == linkURL) {
				lis[i].className += " selected";
			}
		}
	}
}

function removeSelected() {
	var thumbs = document.getElementById("thumbnails");
	var links = thumbs.getElementsByTagName("a");
	for (var i=0; i <links.length; i++) {
		links[i].className = links[i].className.replace(new RegExp(" selected\\b"), "");
	}
}

function imageGallery() {
	if(!document.getElementsByTagName || !document.getElementById) {
		return false;
	}
	var imageGallery = document.getElementById("image_gallery");
	
	if(!imageGallery) {
		return false;
	}
	
	var thumbs = document.getElementById("thumbnails");
	var links = thumbs.getElementsByTagName("a");
		
	for (var i=0; i <links.length; i++) {
		links[0].className = " selected";
		links[i].onclick = function() {
			removeSelected();
			this.className += " selected";
			var source = this.getAttribute("href");
			var largeImage = document.getElementById("display").getElementsByTagName("img")[0];
			largeImage.setAttribute("src", source);
			return false;
		}
		links[i].onmouseover=function() {
			this.className+=" over";
		}
		links[i].onmouseout=function() {
			this.className=this.className.replace(new RegExp(" over\\b"), "");
		}
	}
}


function init() {
	setSelection("nav");
	imageGallery();
}
window.onload = init;