function load_menu (current_page)
{
    if (document.images[current_page].name == current_page)
    {
        document.images[current_page].src = '/images/menu_' + current_page +'_on.png';
    }
}

function menu_hover_on (menu_item_id)
{
    document.images[menu_item_id].src = '/images/menu_' + menu_item_id +'_on.png';
}

function menu_hover_off (menu_item_id,current_page)
{
    document.images[menu_item_id].src = '/images/menu_' + menu_item_id +'_off.png';

    if (menu_item_id == current_page)
    {
        document.images[menu_item_id].src = '/images/menu_' + menu_item_id +'_on.png';
    }
}