var TRANSITION_SLIDE_TIME = 1000;         //In milliseconds
var PAUSE_SLIDE_TIME = 3000;              //In milliseconds

var timer;
var timerPeriod = TRANSITION_SLIDE_TIME / 100;
var counter = 0;
var showslideFlag = true;
var image_list = new Array();
var preload_list = new Array();

// put images to preload in this array
totImages = 1;
  preload_list[0] = "haket1.jpg";

var path_to_images = "Images/Slideshow/";

// preload (change path to images if necessary)
function startSlideshow(backgroundImageID) {
  if (document.images) {
    for (var preload_counter=0; preload_counter<preload_list.length; preload_counter++) {
      image_list[preload_counter] = new Image();
      image_list[preload_counter].src = path_to_images + preload_list[preload_counter];
    }
    nextSlide(backgroundImageID);
  }
}

function changeSlide(backgroundImageID) {
  randomImage = Math.floor((totImages-1)*Math.random());
  document.getElementById(backgroundImageID).style.backgroundImage = "url(" + image_list[randomImage].src + ")";
}

function nextSlide(backgroundImageID) {
  if(showslideFlag) {counter++;}
  else {if(counter == 100) {timerPeriod = TRANSITION_SLIDE_TIME / 100;}counter--;}

  changeOpac(counter, backgroundImageID);

  if(counter == 100) {timerPeriod = PAUSE_SLIDE_TIME; showslideFlag = false;}

  if(counter == 0) {changeSlide(backgroundImageID); showslideFlag = true;}

  timer = setTimeout("nextSlide('" + backgroundImageID + "')",timerPeriod);
}

function quitSlideshow() {clearTimeout(timer);}

//change the opacity for different browsers
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}