function drawSubMenu( numMainMenu )
{
  var subMenu = document.getElementById('subMenu_'+numMainMenu);
  if(subMenu)
    subMenu.style.display= "block";
}

function hideSubMenu(numMainMenu)
{
  var subMenu = document.getElementById('subMenu_'+numMainMenu);
  if(subMenu)
    subMenu.style.display= "none";
  
}