function get_ref_to_id(div_id, o_doc)
{
  //Found here: http://www.howtocreate.co.uk/emails/DavidBerman.html
  if(!o_doc)
    {
      o_doc = document;
    }
  if(document.layers)
    {
      if(o_doc.layers[div_id])
        {
          return o_doc.layers[div_id]; 
        }
      else
        {
          //repeatedly run through all child layers
          for(var x = 0, y; !y && x < o_doc.layers.length; x++)
            {
              //on success, return that layer, else return nothing
              y = getRefToDiv(div_id, o_doc.layers[x].document); 
            }
          return y; 
        } 
    }
  if(document.getElementById)
    {
      return document.getElementById(div_id); 
    }
  if(document.all) 
    {
      return document.all[div_id];
    }
  return false;
}

function show_hide(div_id)
{
  div_ref = get_ref_to_id(div_id);

  if (div_ref)
  {
    if (div_ref.style)
    {
      div_ref = div_ref.style;
    }

    if (div_ref.display == "none")
    {
      div_ref.display = "";
    }
    else
    {
      div_ref.display = "none";
    }
  }
}

function show_hide_both(numerical_id)
{
  show_div_id = 'show_' + numerical_id;
  show_hide(show_div_id);

  hidden_div_id = 'hidden_' + numerical_id;
  show_hide(hidden_div_id);
}