fileonentrer = new Image();
fileonentrer.src = "images/entrerOn.png";
fileonquitter = new Image();
fileonquitter.src = "images/quitterOn.png";

function changeOn(stuff) {
  todo = eval("fileon"+stuff+".src")
  document.images[stuff].src = todo;
}
function changeOff(stuff) {
  document.images[stuff].src = "images/"+stuff+"Off.png";
}
function pngfix() {
  var arVersion = navigator.appVersion.split("MSIE")
  var version = parseFloat(arVersion[1])
  if ((version <= 6) && document.all) {
    document.write('<style type="text/css">img {behavior: url(png.htc);</style>');
  }
}