function showPic(whichpic) {
  if (!document.getElementById("placeholder")) return true;
  var source = whichpic.getAttribute("href");
  var placeholder = document.getElementById("placeholder");
  placeholder.setAttribute("src",source);
  return false;
}

function prepareGallery() {
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("thumbs")) return false;
  var gallery = document.getElementById("thumbs");
  var links = gallery.getElementsByTagName("a");
  for ( var i=0; i < links.length; i++) {
	preloadImg(links[i].href);
    links[i].onclick = function() {
      return showPic(this);
	}
    links[i].onkeypress = links[i].onclick;
  }
}

addLoadEvent(prepareGallery);