var backToRoot = "";
var preloadFlag = false;
var imgs = new Array();

function newImage(arg) {
  if (document.images) {
    var newIndex = imgs.length;
    imgs[newIndex] = new Image();
    imgs[newIndex].src = backToRoot + arg;
    return imgs[newIndex];
  }
}

function changeImages() {
  if (document.images && (preloadFlag == true)) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = backToRoot + changeImages.arguments[i+1];
    }
  }
}

function preloadImages(btr) {
  backToRoot = btr;
  if (document.images) {
    MenuHomepage_over = newImage("images/MenuHomepage-over.jpg");
    MenuHistory_over = newImage("images/MenuHistory-over.jpg");
    MenuTherapies_over = newImage("images/MenuTherapies-over.jpg");
    MenuPlans_over = newImage("images/MenuPlans-over.jpg");
    preloadFlag = true;
    //setTimeout("CheckLoaded();",100);
  }
}

function CheckLoaded() {
  for (var i=0; i<imgs.length; i++) {
    tempImage = imgs[i];
    if (!tempImage.complete) {
      setTimeout("CheckLoaded();",100);
      return;
    }
  }
  preloadFlag = true;
}