/*
This script needs a photo_files array, a photo_descriptions array, a photo_credits array and a current_photo variable to work
*/
var current_opacity = 100;
var direction = 0;
var update_opacity_interval = null;
var img = new Array();
var preload_count = 0;

if (current_photo != 0)
	preload(photo_files[current_photo - 1]);

if (current_photo != photo_files.length - 1)
	preload(photo_files[current_photo + 1]);

function preload(source)
{
	img[preload_count] = new Image();
	img[preload_count].src = source;
	preload_count ++;
}

function changeImage(photo)
{
	clearInterval(update_opacity_interval);
	
	if (photo == "p")
		current_photo--;
	if (photo == "n")
		current_photo++;
	if (photo != "p" && photo != "n")
		current_photo = photo;
	
	if (current_photo == 0)
		document.getElementById("pf_previous").style.display = "none";
	else
	{
		document.getElementById("pf_previous").style.display = "block";
		preload(photo_files[current_photo - 1]);
	}
	
	if (current_photo == photo_files.length - 1)
		document.getElementById("pf_next").style.display = "none";
	else
	{
		document.getElementById("pf_next").style.display = "block";
		preload(photo_files[current_photo + 1]);
	}
	
	document.getElementById("pf_description").innerHTML = photo_descriptions[current_photo];
	document.getElementById("pf_credit").innerHTML = photo_credits[current_photo];
	
	var current_opacity = 100;
	direction = 0;
	
	update_opacity_interval = setInterval("updateOpacity()", 20);
}

function updateOpacity()
{
	if (direction == 0)
		current_opacity = current_opacity - 5;
	else
		current_opacity = current_opacity + 5;
	
	var object = document.getElementById("pf_img").style;
    object.opacity = (current_opacity / 100);
    object.MozOpacity = (current_opacity / 100);
    object.KhtmlOpacity = (current_opacity / 100);
    object.filter = "alpha(opacity=" + current_opacity + ")";
	
	if (current_opacity == 0)
	{
		document.getElementById("pf_img").src = photo_files[current_photo];
		document.getElementById("pf_img").alt = photo_descriptions[current_photo];
		direction = 1;
	}
	if (current_opacity == 100)
		clearInterval(update_opacity_interval);
}// JavaScript Document