userAgent = window.navigator.userAgent;
browserVers = parseInt(userAgent.charAt(userAgent.indexOf("/") + 1), 10);
function newImage(arg){
    if (document.images) {
        rslt = new Image();
        rslt.src = arg;
        return rslt;
    }
}

function findElement(n, ly){
    if (browserVers < 4) 
        return document[n];
    var curDoc = ly ? ly.document : document;
    var elem = curDoc[n];
    if (!elem) {
        for (var i = 0; i < curDoc.layers.length; i++) {
            elem = findElement(n, curDoc.layers[i]);
            if (elem) 
                return elem;
        }
    }
    return elem;
}

function changeImages(){
    if (document.images && (preloadFlag == true)) {
        var img;
        for (var i = 0; i < changeImages.arguments.length; i += 2) {
            img = null;
            if (document.layers) {
                img = findElement(changeImages.arguments[i], 0);
            }
            else {
                img = document.images[changeImages.arguments[i]];
            }
            if (img) {
                img.src = changeImages.arguments[i + 1];
            }
        }
    }
}

var preloadFlag = false;
function preloadImages(){
    if (document.images) {
        home_o = newImage("images/menu/home_o.gif");
        history_o = newImage("images/menu/history_o.gif");
        about_o = newImage("images/menu/about_o.gif");
        resources_o = newImage("images/menu/resources_o.gif");
        membership_o = newImage("images/menu/membership_o.gif");
        gallery_o = newImage("images/menu/gallery_o.gif");
        newsletter_o = newImage("images/menu/newsletter_o.gif");
        links_o = newImage("images/menu/links_o.gif");
        contact_o = newImage("images/menu/contact_o.gif");
        preloadFlag = true;
    }
}