function addLoadListener(fn)
{
  if (typeof window.addEventListener != "undefined")
  {
    window.addEventListener("load", fn, false);
  }
  else if (typeof document.addEventListener != "undefined")
  {
    document.addEventListener("load", fn, false);
  }
  else if (typeof window.attachEvent != "undefined")
  {
    window.attachEvent("onload", fn);
  }
  else
  {
    var oldfn = window.onload;
    if (typeof window.onload != "function")
    {
      window.onload = fn;
    }
    else
    {
      window.onload = function()
      {
        oldfn();
        fn();
      };
    }
  }
}

function attachEventListener(target, eventType, functionRef, capture)
{
  if (typeof target.addEventListener != "undefined")
  {
    target.addEventListener(eventType, functionRef, capture);
  }
  else if (typeof target.attachEvent != "undefined")
  {
    var functionString = eventType + functionRef;
    target["e" + functionString] = functionRef;

    target[functionString] = function(event)
    {
      if (typeof event == "undefined")
      {
        event = window.event;
      }
      target["e" + functionString](event);
    };

    target.attachEvent("on" + eventType, target[functionString]);
  }
  else
  {
    eventType = "on" + eventType;

    if (typeof target[eventType] == "function")
    {
      var oldListener = target[eventType];

      target[eventType] = function()
      {
        oldListener();

        return functionRef();
      }
    }
    else
    {
      target[eventType] = functionRef;
    }
  }
}

function getNextElement(node)
{
  if (node.nodeType == 1)
  {
    return node;
  }

  if (node.nextSibling)
  {
    return getNextElement(node.nextSibling);
  }

  return null;
}

function getPreviousElement(node)
{
  if (node.nodeType == 1)
  {
    return node;
  }

  if (node.previousSibling)
  {
    return getPreviousElement(node.previousSibling);
  }

  return null;
}