/****
 * nav.js - Code to manage site navigation display
 ****/

function openSubMenu( sub_menu_name )
{         
  var ref_menu = document.getElementById(sub_menu_name);
  
  var sub_ul_list    = ref_menu.getElementsByTagName( 'ul' );
  var sub_menu_block = sub_ul_list[0];
  var in_state       = sub_menu_block.style.display;

  var sub_p_list     = ref_menu.getElementsByTagName( 'p' );
  var sub_menu_hdr   = sub_p_list[0];

  collapseAllSubMenus( "navigation" );    
  var button_on = new Image();
  
  if (in_state != 'block')
  {        
    sub_menu_block.style.display = 'block';
    sub_menu_hdr.className       = 'active';
  }
/*   else
  {        
    sub_menu_block.style.display = 'none';
    sub_menu_hdr.className       = '';
  } */
}

function collapseAllSubMenus( nav_elem_name )
{
    var nav_element     = document.getElementById( nav_elem_name );
    var level_one_items = nav_element.getElementsByTagName( 'li' );

    for (idx = 0; idx < level_one_items.length; ++idx)
    {
        if (level_one_items[idx].className == 'nav-lvl1')
        {
            var level_one_paras = level_one_items[idx].getElementsByTagName( 'p' );
            if( level_one_paras.length > 0 ) {
                level_one_paras[0].className = '';
            }
        }
    }
    var tag_list = document.getElementsByTagName('UL');    
    for (var idx = 0; idx < tag_list.length; ++idx)
    {      
        if (tag_list[idx].className == 'nav-lvl2')
        {
            tag_list[idx].style.display = 'none';
        }
    }
}