img_full_size = {
 checkSize: function(img) {
  return ((img.naturalWidth <= img.width) || Element.up(img, 'a'));
 },
 click: function(img){
  if (img_full_size.checkSize(img)) return true;

  $$('img.resizedImgFull').each(function(elem) {
   elem.parentNode.removeChild(elem);
  });

  document.body.appendChild(
   $cE('img')
   .setStyle({position:'absolute',top:document.body.scrollTop,left:document.body.scrollLeft,cursor:'pointer'})
   .addClassName('resizedImgFull')
   .observe('click', img_full_size.close.bindAsEventListener(window))
  ).src=img.src;

  return false;
 },
 close: function(event){
  var img=Event.element(event);
  img.parentNode.removeChild(img);
 },
 mouseover: function(img){
  if (!img_full_size.checkSize(img)) img.style['cursor'] = 'pointer';
 }
};