var cFadeSeconds = 3;
var cFadeStep = 100 / (10 * cFadeSeconds);
var cWaitTime = 100;

var gblFadeIn = 0;
var gblOpacity = 100;
var gblWait = cWaitTime;

function FadeHeaderImage()
{
  var now = new Date();

  if(gblWait > 0)
  {
    gblWait--;
    return;
  }
  
	if(gblFadeIn == 1)
	{
    // Fade in
    if(gblOpacity >= cFadeStep)
    {	   
      gblOpacity -= cFadeStep;
      setOpacity(document.getElementById("header-image"),100 - gblOpacity);
    }
    else
    {
      setOpacity(document.getElementById("header-image"),100);
      gblFadeIn = 0;
      gblOpacity = 100;
      gblWait = cWaitTime;

      // Load the next image
      document.getElementById("div-header").style.backgroundImage = 'url(/header-image.header?' + now.getTime() + ')';
    }
  }
  else
  {
    // Fade out   
    if(gblOpacity >= cFadeStep)
    {	   
      gblOpacity -= cFadeStep;
	    setOpacity(document.getElementById("header-image"),gblOpacity);
    }
    else
    {
      setOpacity(document.getElementById("header-image"),0);
      gblFadeIn = 1;
      gblOpacity = 100;
      gblWait = cWaitTime;
      
      // Load the next image
      document.getElementById("header-image").src = '/header-image.header?' + now.getTime();
    }
  }
}

function setOpacity(obj, opacity)
{
  opacity = (opacity == 100)?99.999:opacity;
    
  // IE/Win
  obj.style.filter = "alpha(opacity:"+opacity+")";
    
  // Safari<1.2, Konqueror
  obj.style.KHTMLOpacity = opacity/100;

  // Older Mozilla and Firefox
  obj.style.MozOpacity = opacity/100;

  // Safari 1.2, newer Firefox and Mozilla, CSS3
  obj.style.opacity = opacity/100;
}

setInterval('FadeHeaderImage()', 100);  // 100mS