var timer, i, menuId;

var dom = document.getElementById ? true : false;
var ie4 = ((document.all) && (!dom)) ? true : false;
var ns4 = document.layers ? true : false;
var opera = navigator.userAgent.indexOf('Opera') != -1 ? true : false;
var dhtml = dom ? true : ie4 ? true : ns4 ? true : false;

if (dhtml) document.write ('<style type="text/css">#menu {position: relative; visibility: hidden; z-index: 1;} #hiddenMenu1 {position: absolute; visibility: hidden; left: 0em; top: 17px;}</style>');
if (dhtml) document.write ('<style type="text/css">#hiddenMenu2 {position: absolute; visibility: hidden; left: 7em; top: 20px;}</style>');
if (dhtml) document.write ('<style type="text/css">#hiddenMenu3 {position: absolute; visibility: hidden; left: 14em; top: 20px;}</style>');
if (dhtml) document.write ('<style type="text/css">#hiddenMenu4 {position: absolute; visibility: hidden; left: 20em; top: 20px;}</style>');



function setVisibility(element,newVisibility)
{ 
  if (dhtml)
  {
    if (dom) document.getElementById(element).style.visibility = newVisibility;
    else if (ie4) document.all[element].style.visibility = newVisibility;
    else if (ns4) eval('document.' + element + '.visibility = newVisibility');
  }
}

function menu()
{
  if (dhtml)
  {
    if (opera) for (i = 1; i <= 4; i++) document.getElementById('hiddenMenu' + i).style.top = 20;
    if (ie4) for (i = 1; i <= 4; i++) document.all['hiddenMenu' + i].style.top = 18;
    setVisibility('menu','visible');
  }
}

function showMenu(id)
{
  if (dhtml)
  {
    clearTimeout(timer);
    for (i = 1; i <= 4; i++) if (i != id) setVisibility((ns4 ? 'menu.document.' : '') + 'hiddenMenu' + i,'hidden');
    setVisibility((ns4 ? 'menu.document.' : '') + 'hiddenMenu' + id,'visible');
  }
}

function hideMenu(id)
{
  if (dhtml)
  {
    menuId = (ns4 ? 'menu.document.' : '') + 'hiddenMenu' + id;
    timer = setTimeout("setVisibility(menuId,'hidden')",1000);
  }
}

function dontHideMenu()
{
  if (dhtml) clearTimeout(timer);
}