function addToFavorites() {
  
  if (window.external)  
       window.external.AddFavorite(location.href,document.title); 
  else   
  if (window.sidebar) 
    window.sidebar.addPanel(document.title,location.href, ""); 
}

var bbOffset = 0;
var bbButtons = $A();
var bbImages = $A();

var bbLinkBack = function() {
	bbPrevImage();
	return false;
}

var bbLinkNext = function(event) {
	Event.stop(event);
	bbNextImage();
	return false;
}

function bbInit() {
	bbOffset = 0;
	bbButtons = $A();
	
	$('left-page').childNodes[0].onclick = bbLinkBack;
	$('right-page').childNodes[0].onclick = bbLinkNext;
	
	$('link-back').onclick = bbLinkBack;
	$('link-next').onclick = bbLinkNext;
	
	
	// remove all children
	$A($('pages').childNodes).each(function(child) {
		child.parentNode.removeChild(child);
	});

	for (var i = 0; i < bbImages.length; i += 2) {
		
		var imageEl = document.createElement('img');
		imageEl.src = '/media/gfx/patrat.gif';
		
		var linkEl = document.createElement('a');
		linkEl.appendChild(imageEl);
		linkEl.href = '';
		linkEl.rel = i;
		
		linkEl.onclick = function() {
			bbOffset = parseInt(this.rel);
			bbDisplay();
			return false;
		}
		
		$('pages').appendChild(linkEl);
		bbButtons.push(imageEl);
	}
	
	var leftImg = $('left-page').firstChild.firstChild;
	
	leftImg.onload = function() {
		leftImg.style.marginTop = (202 - leftImg.height / 2) + 'px';
	};
	
	var rightImg = $('right-page').firstChild.firstChild;
	
	rightImg.onload = function() {
		rightImg.style.marginTop = (202 - rightImg.height / 2) + 'px';
	};
	
	bbDisplay();
}

function bbNextImage() 
{
	if (bbOffset < bbImages.length - 2) {
		bbOffset += 2;
		bbDisplay();	
	}
}

function bbPrevImage() {
	if (bbOffset > 0) {
		bbOffset -= 2;
		bbDisplay();	
	}
}

function bbDisplay() {
	bbInitImage($('left-page'), bbOffset);
	bbInitImage($('right-page'), bbOffset + 1);
	
	bbUpdateLinks();
}

function bbInitImage(el, nr) {

	if (! bbImages[nr]) {
		el.firstChild.style.visibility = 'hidden';
		return;
	}
	
	var img = el.firstChild.firstChild;
	
	img.src = bbImages[nr];
	el.firstChild.style.visibility = 'visible';
}

function bbUpdateLinks() {
	 $('link-back').style.visibility = (bbOffset == 0)
	 	? 'hidden'
	 	: 'visible';

	 $('link-next').style.visibility = (bbOffset < bbImages.length - 2)
		 	? 'visible'
	 	: 'hidden';
	 	
	 bbButtons.each(function(n, i) {
	 	n.src = (i * 2 != bbOffset) 
	 		? '/media/gfx/patrat.gif'
	 		: '/media/gfx/patrat_colorat.gif';
	 });
}