var $ = function(id) { 
  if (typeof(id) == "string")
    return document.getElementById(id);
  return id;
}

var show = function(elt) {
  elt = $(elt);
  elt.style.display='';
} 
var hide = function(elt) {
  elt = $(elt);
  elt.style.display='none';
} 
var toggle = function(elt) {
  elt = $(elt);
  if (elt.style.display == 'none')
    return show(elt);
  return hide(elt);
} 

var observeEvent = function(element, eventName, handler, useCapture) {
  element = $(element);

  if (eventName == 'keypress' && (navigator.appVersion.match(/Konqueror|Safari|KHTML/) || element.attachEvent))
    eventName = 'keydown';

  if (element.addEventListener) {
    element.addEventListener(eventName, handler, false, useCapture);
  } else {
    element.attachEvent("on" + eventName, handler);
  }

  return element;
}