///////////////////////////////////////////////////////////////
// Picture Fade
///////////////////////////////////////////////////////////////
// (c) 2008 by Dominik Scholz, go4u.de Webdesign
// visit: http://www.go4u.de
///////////////////////////////////////////////////////////////

// Settings //
var fade_distance = 5;
var fade_delay = 100;
var fade_pause = 5000;
var fade_numbers = 5;
var fade_path;

// Initialising //
var pic_number = 1;
var opacity = 5;
var opacity_dec = true;

function picfade()
{

	var container = document.getElementById('mainpic');
	var pic1 = container.getElementsByTagName('img')[1];
	var pic2 = container.getElementsByTagName('img')[0];

	if (opacity_dec)
	{
        if (opacity == 0)
        {
            document.getElementById('mainpic_link').href = fade_path+pic_number+'_maxi.jpg';
            cookie_set('pic_number', pic_number);
            pic_number = (pic_number < fade_numbers)? (pic_number+1):1;
            pic1.src = fade_path+pic_number+'.jpg';
			opacity_dec = false;
            window.setTimeout('picfade();', fade_pause);
        }
        else
        {
            opacity = opacity - fade_distance;
            set_opacity(pic1.style, opacity);
            window.setTimeout('picfade();', fade_delay);
        }
	}
	else
	{
        if (opacity == 100)
        {
            document.getElementById('mainpic_link').href = fade_path+pic_number+'_maxi.jpg';
            cookie_set('pic_number', pic_number);
            pic_number = (pic_number < fade_numbers)? (pic_number+1):1;
            pic2.src = fade_path+pic_number+'.jpg';
			opacity_dec = true;
            window.setTimeout('picfade();', fade_pause);
        }
        else
        {
            opacity = opacity + fade_distance;
            set_opacity(pic1.style, opacity);
            window.setTimeout('picfade();', fade_delay);
        }
	}
}

function set_opacity(obj, percentage)
{
	// round, to prevent css errors with strange numbers
	var n_percent = Math.ceil(percentage);
	// "filter"-Style setzen (IE)
    obj.filter="Alpha(opacity="+n_percent+")";
    // "-moz-opacity"-Style setzen (fuer Mozilla)
    obj.MozOpacity=""+n_percent/100;
    // "-khtml-opacity"-Style setzen (fuer Konqueror/Safari)
    obj.KTHMLOpacity=""+n_percent/100;
    // "opacity"-Style setzen (fuer CSS-3-Browser)
    obj.opacity=""+n_percent/100;
}


function picfade_start(path)
{
	if (path == null)
		path = '../img/pics/';

	fade_path = path;

	var p = cookie_get('pic_number');
	var container = document.getElementById('mainpic');

	if (p != null)
		pic_number = parseInt(p);

	if (pic_number > fade_numbers)
		pic_number = 1;

    container.getElementsByTagName('img')[0].src = fade_path+pic_number+'.jpg';
    container.getElementsByTagName('img')[1].src = fade_path+pic_number+'.jpg';
    document.getElementById('mainpic_link').href = fade_path+pic_number+'_maxi.jpg';

	picfade();
}

function cookie_set(name, value)
{
	var date = new Date();
    date.setTime(date.getTime()+(365*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
	document.cookie = name+"="+value;
}

function cookie_get(name)
{
	if (!document.cookie)
		return null;

	var nameis = name + '=';
	var cookies = document.cookie

	cookies = cookies.split(';');

	for (var i=0; i<cookies.length; i++)
	{
		while (cookies[i].charCodeAt(0) == 32)
			cookies[i] = cookies[i].substr(1);

		var item = cookies[i].substr(0, nameis.length);

		if (item == nameis)
			return cookies[i].substr(nameis.length);
	}

	return null;
}