function swapImage(objectID, imageSRC)
{
  document.getElementById(objectID).src = imageSRC;
  document.getElementById(objectID).setAttribute("_SRC", imageSRC);
}

function restoreImage()
{
  var theObject = document.getElementById(objectID);
  var backupAttribute = theObject.getAttribute("_SRC");
  if (backupAttribute)
  {
    theObject.src = backupAttribute;
    theObject.removeAttribute("_SRC");
  }
}