function openNav(trg,myParent){
var childList=trg.childs.split(",");

if(document.getElementById("tr"+childList[0])){
tmpI = 0;
}
else{
tmpI = 1;
}
if(!document.getElementById("tr"+childList[tmpI]))return false;
   if(document.getElementById("tr"+childList[tmpI]).style.display=="block"){
xxx="none";
}
else{
xxx="block";
}

for(var i=0;i<childList.length;i++){

  if(document.getElementById("tr"+childList[i])){
   if(xxx=="none"){document.getElementById("tr"+childList[i]).style.display=xxx}else {if(document.getElementById("tr"+childList[i]).ITEM_PARENT==myParent)document.getElementById("tr"+childList[i]).style.display="block"}
 }
}
}