sfHover = function() {
  var timeout = 600;
  var cssClass = "sfhover";

  var queue = [];
  var reCSS = new RegExp("\\b" + cssClass + "\\b");
  var sfEls = document.getElementById("nav").getElementsByTagName("li");
  for (var i=0; i<sfEls.length; i++) {

    // mouseover and mouseout handlers for regular mouse based interface.
    sfEls[i].onmouseover = function() {
      queueFlush();
      this.className += " " + cssClass;
    }
    sfEls[i].onmouseout = function() {
      queue.push([setTimeout(queueTimeout, timeout), this]);
    }

    // focus and blur handlers for keyboard based navigation.
    sfEls[i].onfocus = function() {
      queueFlush();
      this.className += " " + cssClass;
    }
    sfEls[i].onblur = function() {
      queue.push([setTimeout(queueTimeout, timeout), this]);
    }

    // click event handler needed for tablet type interfaces (e.g. Apple iPhone).
    sfEls[i].onclick = function(e) {
      if (this.className.search(reCSS) == -1) {
        // CSS not set, so clear all sibling (and decendants) menus, and then set CSS on this menu...
        var elems = this.parentNode.getElementsByTagName("li");
        for (var i=0; i<elems.length; i++) {
          elems[i].className = elems[i].className.replace(reCSS, "");
        }
        this.className += " " + cssClass;
      } else {
        // CSS already set, so clear all decendant menus and then this menu...
        var elems = this.getElementsByTagName("li");
        for (var i=0; i<elems.length; i++) {
          elems[i].className = elems[i].className.replace(reCSS, "");
        }
        this.className = this.className.replace(reCSS, "");
      }
      if (e && e.stopPropagation)
        e.stopPropagation();
      else
        window.event.cancelBubble = true;
    }
  }

  queueFlush = function () {
    while (queue.length) {
      clearTimeout(queue[0][0]);
      queueTimeout();
    }
  }

  queueTimeout = function() {
    if (queue.length) {
      var el = queue.shift()[1];
      el.className = el.className.replace(reCSS, "");
    }
  }
}
addLoadEvent(sfHover);
function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}