function openImages() {
	links = document.getElementsByTagName("a");
	for (var i = 0; i < links.length; i++) {
		link = links[i];
		ext = link.href.substring(link.href.lastIndexOf(".")).toLowerCase();

		if (ext == ".jpg" || ext == ".gif") {
			link.target = "_blank"
			link.onclick = loadImage
		}
	}
}

function loadImage() {
	window.open(this.href, '', 'height=640,width=800,scrollbars,resizable');
	return false;
}

openImages();