(function(){
  var loading = new Image();
  loading.src = "imgsite/loading.gif";
  getElementsByClass('picture-view').each(function(pview){
    var thumblist = getFirstOfClass('thumblist', pview);
    var preview   = getFirstOfClass('preview', pview);
    var thumbs    = getAll('a', thumblist);
    var next      = null;
    var prev      = null;
    function swapPic(ev){
      var a = ev.currentTarget;
      doSwap(a);
      ev.preventDefault();
    }
    function doSwap(a){
      if (!a) return;
      remClass(preview, 'hidden');
      var index = thumbs.indexOf(a);
      prev = thumbs[index - 1];
      next = thumbs[index + 1];
      var img_url = a.href;
      preview.src = loading.src;
      a.href = '#';
      setTimeout(function(){ preview.src = img_url; a.href = img_url }, 0)
    }
    addEvent(thumbs, 'click', swapPic);
    var next_bt = getFirstOfClass('next', pview);
    var prev_bt = getFirstOfClass('prev', pview);
    if (next_bt) addEvent(next_bt, 'click', function(){ doSwap(next) })
    if (prev_bt) addEvent(prev_bt, 'click', function(){ doSwap(prev) })
  });
})()