var lastOpenedSection = "";
var lastOpenedSubsection = "";

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";
}