// JavaScript Document

var imgnum = 0;
var tag = 1;
var blend_dur = 1000;
var blend_steps = 10;
var show_dur = 5000;
var ie = false;
var cr_string = '© by: ';
var cr = null;
var crs = null;

function startFade(fls, id) {
	var el1 = document.getElementById( id + '_1' );
	var el2 = document.getElementById( id + '_2' );
	el = [el1, el2];
	
	ie = el1.filters?true:false;
	files = fls;
	preload();
	
	if (startFade.arguments.length > 2) {
		crs = startFade.arguments[2];
		cr = document.getElementById(id + '_cr');
	}
	
	fadeLoop();
}

function fadeLoop() {
	fade(tag, 0, -1);
	tag = (tag + 1) % el.length;
	
	if (cr != null && crs != null)
		cr.firstChild.data = cr_string + crs[imgnum];
	
	el[tag].src = imgdir + '/' + nextpic();
	fade(tag, 0, 1);
	
	setTimeout("fadeLoop()", blend_dur + show_dur);
}

function fade(element, progress, dir) {
	if (progress < 1) {
		progress += 1 / blend_steps;
		if (dir < 0) value = 1 - progress;
		else value = progress;
		
		value = (Math.round(value * 10)) / 10;
		
		if( ie ) el[element].style.filter = 'Alpha(opacity=' + value * 100 + ')';
		else el[element].style.opacity = value;
		
		setTimeout( "fade(" + element + ", " + progress + ", " + dir + " )", blend_dur / blend_steps );
	}
}

function nextpic() {
	var pic = files[ imgnum ];
	imgnum = (imgnum + 1) % files.length;
	return pic;
}

function preload() {
	var im;
	for (var i = 0; i < files.length; i++) {
		im = new Image();
		im.src = imgdir + '/' + files[i];
	}
}