Object.extend(Position, {
	windowBounds: function() {
		var x = window.innerWidth
			|| document.documentElement.clientWidth
			|| document.body.clientWidth
			|| 0;
		var y = window.innerHeight
			|| document.documentElement.clientHeight
			|| document.body.clientHeight
			|| 0;
		return [x, y];
	}
});
Object.extend(Element, {
	fullscreen: function(element, zindex) {
		element = $(element);
		element.style.position = "fixed";
		element.style.left = element.style.top = 0;
		element.style.bottom = element.style.right = 0;
		element.style.zIndex = zindex;
	},
	center: function(element, zindex) {
		element = $(element);
		var extent = Element.getDimensions(element);
		var bounds = Position.windowBounds();
		var x = (bounds[0] - extent.width) / 2;
		var y = (bounds[1] - extent.height) / 2;
		x = x < 0 ? 0 : x; y = y < 0 ? 0 : y;
		element.style.position = "absolute";
		element.style.left = x + "px";
		element.style.top = y + "px";
		element.style.zIndex = zindex;
	}
});
function updateLightboxLevel(level) {
	Element.fullscreen("overlay"+level, 9000+level*2);
	Element.center("lightbox"+level, 9001+level*2);
	Element.show("lightbox"+level);
};
function closeLightboxLevel(level) {
	$("overlay"+level).replace("");
	$("lightbox"+level).replace("");
};
function updateLightbox() {
	updateLightboxLevel(0);
};
function closeLightbox() {
	closeLightboxLevel(0);
};