// Rotating images with cross-browser fade effect
// Written by Lars Michael Astrom
// Opacity Change code from: 
// http://www.brainerror.net/scripts_js_blendtrans.php
// Modified by Lars Michael Astrom
// 2007 A3 IT Solutions

var numImgs = 4; // number of images
var speed = 3000;

fade();
function fade(){
  for (var i = 1; i < numImgs + 1; i++){
    var div = "div" + i;
    var t = setTimeout("opacity('" + div + "',100,0,1000)",speed * i);
  }
  
  setTimeout("resetDivs();",(speed * (numImgs + 1)));
}

function resetDivs(){
  for (var j = 1; j < numImgs + 1; j++){
    var div = "div" + j;
    opacity(div,0,100,0);
  }
  
  fade();
}

// function to change opacity
function opacity(id, opacStart, opacEnd, millisec) {
  var speed = Math.round(millisec / 100); //speed for each frame
  var timer = 0;

  // determine the direction for the blending, if start and end are the same nothing happens
  if(opacStart > opacEnd) {
    for(i = opacStart; i >= opacEnd; i--){
      setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
      timer++;
    }
  }else if(opacStart < opacEnd){
    for(i = opacStart; i <= opacEnd; i++){
      setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
      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 + ")";
}