var switchTimeout = null;
var switchImageSeconds = 3;
var startZindex = 10;
var imageLinks = Array("industrieel", "maritiem", "design", "machines", "tekenwerk");
var currentSlideShowImage = -1;
var currentImage = null;
var currentLink = null;
var currentZindex = null;

if (!Array.prototype.indexOf)
{
  Array.prototype.indexOf = function(elt /*, from*/)
  {
    var len = this.length;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

function init()
{
	for(var i = 0; i<imageLinks.length; i++)
	{
		$(imageLinks[i]+'_arrow').onmouseover = function(){stopSlideShow();userSwitchImage(this);};
		$(imageLinks[i]+'_arrow').onmouseout = function(){startSlideShow(this);};
		$(imageLinks[i]+'_img').style.zIndex = startZindex+i;
	}
	continueSlideShow(-1);
}

function userSwitchImage(obj)
{
	if(currentLink!=null)
		currentLink.style.background = "url(../media/arrow.png)";
	obj.style.background = "url(../media/arrow-hover.png)";
	currentLink = obj;
	if(currentImage!=null && currentZindex!=null)
		currentImage.style.zIndex = currentZindex;
	var hoveredImage = $(obj.name+'_img');
	currentImage = hoveredImage;
	currentZindex = currentImage.style.zIndex;
	currentImage.style.zIndex = (startZindex+10);
}

function switchImage(imgNr)
{
	userSwitchImage($(imageLinks[imgNr]+'_arrow'));
}

function startSlideShow(obj)
{
	currentSlideShowImage = imageLinks.indexOf(obj.name);
	switchTimeout = setTimeout('continueSlideShow('+currentSlideShowImage+')',(switchImageSeconds*1000));
}

function continueSlideShow(imgNr)
{
	currentSlideShowImage = imgNr;
	if(imageLinks.length > 0)
	{
		var newImageNr = currentSlideShowImage+1;
		if(newImageNr>=imageLinks.length)
			newImageNr=0;
		switchImage(newImageNr);
		switchTimeout = setTimeout('continueSlideShow('+newImageNr+')',(switchImageSeconds*1000));
	}
}

function stopSlideShow()
{
	clearTimeout(switchTimeout);	
}

function $(obj)
{
	return document.getElementById(obj);	
}

function startPreload(preloaderbox)
{
	var objBody = document.getElementsByTagName("body").item(0);
	//$('sitecontainer').style.display = "none";
	//objBody.onLoad = function(){alert('klaar');};
	window.onload = function()
	{
		$('preloader').style.display = "none";
		$('sitecontainer').style.display = "block";
		setupOverlayer();
	};
}