opera = (navigator.userAgent.indexOf('Opera') >= 0)? true : false;
ie = (document.all && !opera)? true : false;
dom = (document.getElementById && !ie && !opera)? true : false;

var now = new Date();
fixDate(now);
now.setTime(now.getTime() + 365 * 24 * 60 * 60 * 1000);

treeOpen = new Array();

treeOpen['zero'] = false;
treeOpen['second'] = false;
treeOpen['first'] = false;
treeOpen['third'] = false;
treeOpen['fourth'] = false;
treeOpen['fifth'] = false;
treeOpen['sixth'] = false;
treeOpen['seventh'] = false;

treeItems = new Array();

treeItems['zero'] = new Array ('zero');
treeItems['first'] = new Array ('first');
treeItems['second'] = new Array('second');
treeItems['third'] = new Array('third');
treeItems['fourth'] = new Array('fourth');
treeItems['fifth'] = new Array('fifth');
treeItems['sixth'] = new Array('sixth');
treeItems['seventh'] = new Array('seventh');

function setCookie(name, value, expires, path, domain, secure) {
  var curCookie = name + "=" + escape(value) +
      ((expires) ? "; expires=" + expires.toGMTString() : "") +
      ((path) ? "; path=" + path : "") +
      ((domain) ? "; domain=" + domain : "") +
      ((secure) ? "; secure" : "");
  document.cookie = curCookie;
}

function getCookie(name) {
  var dc = document.cookie;
  var prefix = name + "=";
  var begin = dc.indexOf("; " + prefix);
  if (begin == -1) {
    begin = dc.indexOf(prefix);
    if (begin != 0) return null;
  } else
    begin += 2;
  var end = document.cookie.indexOf(";", begin);
  if (end == -1)
    end = dc.length;
  return unescape(dc.substring(begin + prefix.length, end));
}

function deleteCookie(name, path, domain) {
  if (getCookie(name)) {
    document.cookie = name + "=" + 
    ((path) ? "; path=" + path : "") +
    ((domain) ? "; domain=" + domain : "") +
    "; expires=Thu, 01-Jan-70 00:00:01 GMT";
  }
}

function fixDate(date) {
  var base = new Date(0);
  var skew = base.getTime();
  if (skew > 0)
    date.setTime(date.getTime() - skew);
}

function changeTree(which) {
  if (treeOpen[which])
  {
    for (i in treeItems[which]) 
		removeElem(treeItems[which][i]);
    treeOpen[which] = false;
    if ( getCookie(which) ) {deleteCookie(which);}

  } 
  else
  {
    for (i in treeItems[which])
      putElem(treeItems[which][i],"table-row");
    treeOpen[which] = true;
    if ( !(getCookie(which)) ) {setCookie( which, "on", now);}
  }
}

function putElem(elemId,displayValue) {
  if (dom) document.getElementById(elemId).style.display = (displayValue)? displayValue : "block";
  else if (ie) document.all[elemId].style.display = "block";
}

function removeElem(elemId) {
  if (dom) document.getElementById(elemId).style.display = "none";
  else if (ie) document.all[elemId].style.display = "none";
}

if (dom || ie) {
  document.writeln('<style type="text/css">');
  document.writeln('.treeElem \{ display: none; \}');
  document.writeln('</style>');
}