function getbyid(id)
{
	itm = null;
	
	if (document.getElementById)
	{
		itm = document.getElementById(id);
	}
	else if (document.all)
	{
		itm = document.all[id];
	}
	else if (document.layers)
	{
		itm = document.layers[id];
	}
	
	return itm;
}

function hide_item(item)
  {
    if ( ! item ) return;
	
    item.style.display = "none";
  }

function show_item(item)
  {
    if ( ! item ) return;

    item.style.display = "";
  }

function show(itm_id)
  {
    hide_item( getbyid('itm_hiddenhead_'+itm_id) );
    show_item( getbyid('itm_showhead_'+itm_id) );
    show_item( getbyid('itm_'+itm_id) );
  }

function hide(itm_id)
  {
    hide_item( getbyid('itm_showhead_'+itm_id) );
    show_item( getbyid('itm_hiddenhead_'+itm_id) );
    hide_item( getbyid('itm_'+itm_id) );
  }