function hookEvent(element, eventName, callback, bobble)
{
  if(typeof(element) == "string")
    element = document.getElementById(element);
  if(element == null)
    return;
  if(element.addEventListener)
    element.addEventListener(eventName, callback, true);
  else if(element.attachEvent)
    element.attachEvent("on" + eventName, callback);
}

function unhookEvent(element, eventName, callback)
{
  if(typeof(element) == "string")
    element = document.getElementById(element);
  if(element == null)
    return;
  if(element.removeEventListener)
    element.removeEventListener(eventName, callback, false);
  else if(element.detachEvent)
    element.detachEvent("on" + eventName, callback);
}

function getEvent(e)
{
  if(!e)
    return window.event
  return e;
}

function cancelEvent(e)
{
  if(!e)
    e = window.event;
  if(e.stopPropagation)
    e.stopPropagation();
  if(e.preventDefault)
    e.preventDefault();
  e.cancelBubble = true;
  e.cancel = true;
  e.returnValue = false;
  return false;
}