var swap_preload = new Array();
function hookEvent(e, hook, func)
{
  if(e.addEventListener) e.addEventListener(hook, func, false);
  else if(e.attachEvent) e.attachEvent("on" + hook, func);
}
function swap_makeswapname(src)
{
  return src.replace(/(\.[^\.]+)$/, '_on$1');
}
function setup_swap()
{
  var e, i;
  e = document.getElementsByTagName('img');
  for(i = 0; i < e.length; ++i) {
    var img = e[i], pimg;
    if(img.className == 'swaptarget') {
      hookEvent(img, "mouseover", swap_mouseover);
      hookEvent(img, "mouseout", swap_mouseout);
      img.originalsrc = img.src;
      pimg = new Image();
      pimg.src = swap_makeswapname(img.src);
      swap_preload[swap_preload.length] = pimg;
    }
  }
}
function swap_mouseover(ev)
{
  var e = window.event ? event.srcElement : ev.target;
  e.src = swap_makeswapname(e.src);
}
function swap_mouseout(ev)
{
  var e = window.event ? event.srcElement : ev.target;
  e.src = e.originalsrc;
}

hookEvent(window, "load", setup_swap);