function showSubMenu(id)
{
  for(i=1; i<=3; i++)
  {
    var menu = document.getElementById('divMenu' + i);
    menu.className = "NonSelectedMenu";
    var subMenu = document.getElementById('subMenu'+ i);
    subMenu.style.display = "none";
  }
  document.getElementById('subMenu'+id).style.display = "";
  document.getElementById('divMenu'+id).className = "SelectedMenu";
}