var loadedImages  = new Array();
var swappedImages = new Array();

function LoadImages ()
{
    var i, j, k;
    if (document.images) {
        k = loadedImages.length;
        for (i in LoadImages.arguments) {
            for (j in LoadImages.arguments[i]) {
                loadedImages[k] = new Image;
                loadedImages[k].src = j;
                k++;
            }
        }
    }
}

function SwapImage (imgName, imgSrc)
{
    var x, i;
    if ((x = document.images[imgName]) != null) {
        i = swappedImages.length;
        swappedImages[i] = new Image;
        swappedImages[i].name = x.name;
        swappedImages[i].src = x.src;
        x.src = imgSrc;
    }
}

function SwapImgRestore ()
{
    var i, x;
    if (document.images) {
        while (i = swappedImages.shift()) {
            x = document.images[i.name];
            x.src = i.src;
        }
    }
}



var mainNavImages = new Array(
    'images/nav_overview_n.gif',    'images/nav_overview_h.gif',
    'images/nav_wood_n.gif',        'images/nav_wood_h.gif',
    'images/nav_gallery_n.gif',     'images/nav_gallery_h.gif',
    'images/nav_environment_n.gif', 'images/nav_environment_h.gif',
    'images/nav_links_n.gif',       'images/nav_links_h.gif'
);

var overviewNavImages = new Array(
    'images/navo_history_n.gif',      'images/navo_history_h.gif',
    'images/navo_faq_n.gif',          'images/navo_faq_h.gif',
    'images/navo_partnerships_n.gif', 'images/navo_partnerships_h.gif',
    'images/navo_benefits_n.gif',     'images/navo_benefits_h.gif'
);

var woodNavImages = new Array(
    'images/navw_facts_n.gif',       'images/navw_facts_h.gif',
    'images/navw_loggers_n.gif',     'images/navw_loggers_h.gif',
    'images/navw_source_n.gif',      'images/navw_source_h.gif',
    'images/navw_history_n.gif',     'images/navw_history_h.gif',
    'images/navw_sustainable_n.gif', 'images/navw_sustainable_h.gif',
    'images/navw_benefits_n.gif',    'images/navw_benefits_h.gif'
);

var galleryNavImages = new Array(
    'images/navg_photo_n.gif',  'images/navg_photo_h.gif',
    'images/navg_videos_n.gif', 'images/navg_videos_h.gif',
    'images/navg_boiler_n.gif', 'images/navg_boiler_h.gif'
);

var environmentNavImages = new Array(
    'images/nave_emission_n.gif',    'images/nave_emission_h.gif',
    'images/nave_renewable_n.gif',   'images/nave_renewable_h.gif',
    'images/nave_sustainable_n.gif', 'images/nave_sustainable_n.gif'
);

var linksNavImages = new Array(
    'images/navl_news_n.gif',    'images/navl_news_h.gif',
    'images/navl_related_n.gif', 'images/navl_related_h.gif'
);