// Define toc item
function tocItem(dir, name, width, height)
{
  this.on = new Image();
  this.on.src = dir + "/" + name + "on.gif"
  this.off = new Image();
  this.off.src = dir + "/" + name + "off.gif"
}

// Alloc new toc item
function tocItemNew(dir, name) 
{
  tocItem[name] = new tocItem(dir, name);
}

// Active toc image
function tocImgAct(imgName,status) 
{
  if (document.images != null)
  {
    document[imgName].src = tocItem[imgName].on.src;
    if (status!=null) window.status=status
  }
}

// Inactive toc image
function tocImgInact(imgName) 
{
  if (document.images)
    document [imgName].src = tocItem[imgName].off.src;
}

// Load table of contents
// name  - Elements name
// numEl - Number of elements to load
function tocLoad(dir, name, numEl) 
{
  if (document.images != null) 
     for (i = 0; i <= numEl-1; i++) tocItemNew(dir, name + i);
}