function show_id(id, mode)
{ if(object = document.getElementById(id))
  { if(mode) object.style.display = 'block';
    else object.style.display = 'none';
    if(object = document.getElementById(id + '_alt'))
    { if(!mode) object.style.display = 'block';
      else object.style.display = 'none';
    }
  }
}

function show_id_auto(id)
{ if(object = document.getElementById(id))
  { if(object.style.display == 'none') object.style.display = 'block';
    else object.style.display = 'none';
  }
}