var fps = 10;
function fade(img, time, dir){
  img = document.getElementById(img);
  var steps = time * fps;
  if (typeof img.style.opacity != 'undefined'){var otype = 'w3c';}
  else if (typeof img.style.MozOpacity != 'undefined'){otype = 'moz';}
  else if (typeof img.style.KhtmlOpacity != 'undefined'){otype = 'khtml';}
  else if (typeof img.filters == 'object'){otype = (img.filters.length > 0 && typeof img.filters.alpha == 'object' && typeof img.filters.alpha.opacity == 'number') ? 'ie' : 'none';}
  else { otype = 'none'; }
  if (otype != 'none'){if (dir == 'out') { dofade(steps, img, 1, false, otype); }
    else { dofade(steps, img, 0, true, otype); }}}


function dofade(steps, img, value, targetvisibility, otype){ 
value += (targetvisibility ? 1 : -1) / steps;
  if (targetvisibility ? value > 1 : value < 0) value = targetvisibility ? 1 : 0; setfade(img, value, otype);
  if (targetvisibility ? value < 1 : value > 0) 
  { setTimeout(function() {dofade(steps, img, value, targetvisibility, otype);}, 1000 / fps);}
}

function setfade(img, value, otype){
  switch(otype)  {
    case 'ie': img.filters.alpha.opacity = value * 100;break;
    case 'khtml': img.style.KhtmlOpacity = value;break;
    case 'moz':img.style.MozOpacity = (value == 1 ? 0.9999999 : value);break;
    default: img.style.opacity = (value == 1 ? 0.9999999 : value);}
}