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">');
 document.write ('#scriptSupport {display: none;}');
 document.write ('#menuHolder {position: relative; visibility: hidden; z-index: 1;}');
 document.write ('#hiddenMenu1, #hiddenMenu2, #hiddenMenu3, #hiddenMenu4 {position: absolute; visibility: hidden;}');
 document.write ('#visibleMenu1 {position: absolute; left: 10px; top: 54px;}');
 document.write ('#visibleMenu2 {position: absolute; left: 115px; top: 54px;}');
 document.write ('#visibleMenu3 {position: absolute; left: 240px; top: 54px;}');
 document.write ('#visibleMenu4 {position: absolute; left: 530px; top: 54px;}');

 document.write ('#hiddenMenu1 {left: 5px; top: 73px;}');
 document.write ('#hiddenMenu2 {left: 115px; top: 73px;}');
 document.write ('#hiddenMenu3 {left: 240px; top: 73px;}');
 document.write ('#hiddenMenu4 {left: 530px; top: 73px;}');

 document.write ('</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('menuHolder','visible');
  }
}

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

function hideMenu(id)
{
  if (dhtml)
  {
    menuId = (ns4 ? 'menuHolder.document.' : '') + 'hiddenMenu' + id;
    timer = setTimeout("setVisibility(menuId,'hidden')",50);
  }
}

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