var subMenuTimer;

function ShowSubMenu(divID) {
  HideAllSubMenus();
  clearTimeout(subMenuTimer);
  
  var div = document.getElementById(divID);
  if(div)
    div.style.visibility = "visible";
}

function HideSubMenu(divID) {
  subMenuTimer = setTimeout("HideSubMenuNow('" + divID + "')", 500);
}

function HideSubMenuNow(divID) {
  var div = document.getElementById(divID);
  if(div)
    div.style.visibility = "hidden";
}

function HideAllSubMenus() {
  for(i = 0; i < subMenuIDs.length; i++)
    HideSubMenuNow(subMenuIDs[i]);
}