var lastOpenedSection = "";
var lastOpenedSubsection = "";
var startY = 150;
var sy;

function floatMenu() {
  if(document.documentElement.scrollTop)
  {
    sy = document.documentElement.scrollTop;
  }
  else
  {
    sy = document.body.scrollTop;
  }

  var temp = sy + startY;

  if (temp > 250)
    temp -= 100;

  var newY = temp.toString() + "px";

  var elem = document.getElementById("SiteMenu");
  elem.style.top = newY;
}

function toggleSection(strID) {

 if (lastOpenedSection == strID) {
   if (lastOpenedSubsection != "")
     collapseItem(lastOpenedSubsection);
   collapseItem(strID);
   lastOpenedSection = "";
 }
 else if (lastOpenedSection == "") {
   expandItem(strID);
   lastOpenedSection = strID;
 }
 else {
   if (lastOpenedSubsection != "")
     collapseItem(lastOpenedSubsection);
   collapseItem(lastOpenedSection);
   expandItem(strID);
   lastOpenedSection = strID;
 }

 lastOpenedSubsection = "";
}

function toggleSubsection(strID) {
 if (lastOpenedSubsection == strID) {
   collapseItem(strID);
   lastOpenedSubsection = "";
 }
 else if(lastOpenedSubsection == "") {
   expandItem(strID);
   lastOpenedSubsection = strID;
 }
 else {
   collapseItem(lastOpenedSubsection);
   expandItem(strID);
   lastOpenedSubsection = strID;
 }
}

function collapseItem(strID) {
 document.getElementById(strID).style.display = "none";
}

function expandItem(strID) {
 document.getElementById(strID).style.display = "block";
}

window.onscroll = floatMenu;