var old_key = -1;

Event.onDOMReady(function() { 
	setTimeout(fade_img, 4000);
});

function fade_img()
{
	var random_key = rand(total_images, old_key);
	old_key = random_key;
	random_key = random_key - 1;
	
	var title = img_array[random_key][0];
	var desc = img_array[random_key][1];
	var url = img_array[random_key][2];
	var href = img_array[random_key][3];
	
	var promo_item = new Element('div');
	promo_item.addClassName('promo_item');
	promo_item.update("<p id='image_link'><a href='" + href + "'><img class='home' src='" + url + "' alt='sample wildlife image' height='360' /></a></p><p id='image_text'><a href='" + href + "'><strong>" + title + "</strong></a><br />" + desc + "</p>");
	promo_item.setStyle({position: 'absolute', left: '0', top: '0', width: '600px'});
	promo_item.setOpacity('0');
	
	$('promo_item_wrapper').appendChild(promo_item);
	
	var promo_items = $('promo_item_wrapper').childElements();
	
	new Effect.Fade(promo_items[0], {duration: 5});
	new Effect.Appear(promo_items[1], {duration: 5});
	
	setTimeout(function() {
		promo_items[0].remove();
		promo_items[1].setStyle({position: 'relative'});
	}, 5000);
	
	setTimeout(fade_img, 9000);
	
}

function rand(num, old)
{
	var key = Math.floor(Math.random() * num + 1)
	
	while (key == old)
	{
		key = rand(num, key);
	}
	
	return key;
}