var itemId = '';
var iconId = '';
var rowId = '';

function ajaxDisplayItem(item_index, class_id, node_id)
{ if (itemId != '')
  { Element.removeClassName(rowId, 'selected');
    Element.hide(iconId, itemId);
    $(itemId).innerHTML = '';
  }
  var newId = 'item_id_' + item_index;
  if (itemId != newId)
  { itemId = newId;
    iconId = 'icon_id_' + item_index;
    rowId = 'row_id_' + item_index;
    var url = '/gui/display/' + class_id + '/' + node_id;
    var ajax = new Ajax.Request(url, {method: 'get', onComplete: ajaxDisplayItemComplete});
  }
  else
    itemId = '';
}

function ajaxDisplayItemComplete(request)
{ Element.addClassName(rowId, 'selected');
  $(itemId).innerHTML = request.responseText;
  Element.show(itemId, iconId);
}