var TimeToFade = 1000.0;

function fade(eid, eidalt)
{
  var element = document.getElementById(eid);
  if(element == null)
    return;
   
  if(element.FadeState == null)
  {
    if(element.style.opacity == null
        || element.style.opacity == ''
        || element.style.opacity == '1')
    {
      element.FadeState = 2;
    }
    else
    {
      element.FadeState = -2;
    }
  }
   
  if(element.FadeState == 1 || element.FadeState == -1)
  {
    element.FadeState = element.FadeState == 1 ? -1 : 1;
    element.FadeTimeLeft = TimeToFade - element.FadeTimeLeft;
  }
  else
  {
    element.FadeState = element.FadeState == 2 ? -1 : 1;
    element.FadeTimeLeft = TimeToFade;
    setTimeout("animateFade(" + new Date().getTime() + ",'" + eid + "','" + eidalt + "')", 33);
  }  
}

function animateFade(lastTick, eid, eidalt)
{  
  var curTick = new Date().getTime();
  var elapsedTicks = curTick - lastTick;
 
  var element = document.getElementById(eid);
  var elementalt = document.getElementById(eidalt);
 
  if(element.FadeTimeLeft <= elapsedTicks)
  {
    element.style.opacity = element.FadeState == 1 ? '1' : '0';
    element.style.filter = 'alpha(opacity = '
        + (element.FadeState == 1 ? '100' : '0') + ')';

    elementalt.style.opacity = element.FadeState == 1 ? '0' : '1';
    elementalt.style.filter = 'alpha(opacity = '
        + (element.FadeState == 1 ? '0' : '100' ) + ')';

    element.FadeState = element.FadeState == 1 ? 2 : -2;
	return;
  }
 
  element.FadeTimeLeft -= elapsedTicks;
  var newOpVal = element.FadeTimeLeft/TimeToFade;
  if(element.FadeState == 1)
    newOpVal = 1 - newOpVal;

  element.style.opacity = newOpVal;
  element.style.filter = 'alpha(opacity = ' + (newOpVal*100) + ')';

  elementalt.style.opacity = 1 - newOpVal;
  elementalt.style.filter = 'alpha(opacity = ' + ((1 - newOpVal)*100) + ')';
  
  setTimeout("animateFade(" + curTick + ",'" + eid + "','" + eidalt + "')", 33);
}

function load()
{
timeimgs('0');
}

function timeimgs(numb) { // Reusable timer
thetimer = setTimeout("imgturn('" +numb+ "')", 5000);
}

function imgturn(numb) { // Reusable image turner
fade('front','back');
++numb;
timeimgs(numb);
}