function updateLightbox() {
	if ( !(window.document.body==$('overlay').parentNode) ) {
		Position.makeAbsolute('overlay');
		Position.makeAbsolute('lightbox');
	}
	Element.fullscreen("overlay");
	Element.center("lightbox");
};
function showLightbox() {
	hideScrollbars();
	updateLightbox();
	addResizeEvent(
		function() {
			updateLightbox();
		}
	);
	new Effect.Parallel(
    [ new Effect.Appear('overlay',{to:0.5,sync: true}), 
      new Effect.Appear('lightbox',{sync: true}) ],
		{duration:0.4}
  );
	/*updateLightbox();
	new Effect.Appear('overlay',{duration:0.3,to:0.5});
	new Effect.Appear('lightbox',{duration:0.3});*/
}
function hideLightbox() {
  new Effect.Parallel(
    [ new Effect.Fade('overlay',{sync: true}), 
      new Effect.DropOut('lightbox',{sync: true}) ],
		{duration:0.4}
  );
  showScrollbars();
}