/**
 * dotred slideshow fade (http://www.dotred.be)
 *
 * This JavaScript code is used to show a slideshow with fading effect without using any library or framework.
 * 
 * Version 1.0
 * 
 * 30 May 2011
 *
 * Copyright (c) 2011 Dotred, Bart Leemans
 * Licensed under the GPL licenses.
 * http://www.gnu.org/licenses/gpl.txt
 **/
 
var currentSlide = 1;
var maxSlides = 0;

function fadeImage(){
	opacity = 100;
	if(steps < 4){
		steps += 1;
		opacity = opacity / steps;
		imageObj = document.getElementById("slide-"+currentSlide);
		imageObjN = document.getElementById("slide-"+nextSlide);
		imageObjN.style.display = "block";

		imageObj.style.opacity = "" + opacity / 100;
		imageObjN.style.opacity = "" + ((steps * 25) / 100);
		//fade
		slideTimeout = setTimeout("fadeImage()", 170); /** fade transition speed */
	}else{
		steps = 1;
		document.getElementById("slide-"+currentSlide).style.display = "none";
		currentSlide += 1;
		if(currentSlide > maxSlides){
			currentSlide = 1;
		}
		showSlide();
	}
}

function initSlideshow(){
	slidesCollection = document.getElementById("slides").children;
	maxSlides = slidesCollection.length;
	for (var i=0; i < maxSlides; i++){
		slidesCollection[i].id = "slide-"+(i+1);
		if (i > 0)
			slidesCollection[i].style.display = "none";
	}	
	steps = 1;
	nextSlide = 2;
	slideTimeout = 0;
	showSlide();
}

function showSlide(){
	clearTimeout(slideTimeout);
		
	nextSlide = currentSlide + 1;
	if (currentSlide >= maxSlides){
		nextSlide = 1;
	}
	
	slideTimeout = setTimeout("fadeImage()", 8300); /** display time of slide */
}