function DisplaySubNavigation(navId)
{
  var elm1 = document.getElementById(navId);
  if (elm1 != null)
    elm1.style.display = "block";
}

function HideSubNavigation(navId)
{
  var elm1 = document.getElementById(navId);
  if (elm1 != null)
    elm1.style.display = "none";
}