//var imgdir = 'img/'
//var bkgds = new Array("menu-bg.gif", "menu-bg2.gif", "menu-bg3.gif", "menu-bg4.gif")

function preload_menu_backgrounds(bkgds,prfx) {
    var loaded_bkgds = new Array();
    var i, j, l, already_loaded;
    for (i=0; i<bkgds.length; i++) {
        for (j=0,already_loaded=0,l=loaded_bkgds.length; j<l; j++) {
            if (loaded_bkgds[j].src == prfx + bkgds[i]) {
                already_loaded = 1;
                break;
            }
        }
        if (! already_loaded) {
            loaded_bkgds[l] = new Image();
            loaded_bkgds[l].src = prfx + bkgds[i];
        }
    }
    return true;
}

function set_background (o,i) {
    o.style.backgroundImage = 'url('+i+')';
}

var win = false;

function rotate_images () {
    var l = this.menu_link;
    l.i = (l.i+1) % l.imgs.length;
    set_background(l.sfondo, l.imgs[l.i]);
}

function stickbg () {
    this.menu_link.ancora.onmouseout = null;
}

function Menu_link (a,s) {
    this.ancora = a;
    this.sfondo = s;
    this.imgs = new Array();
    this.i = 0;
    this.rotate_images = rotate_images;
    this.stickbg = stickbg;
}



var menu_links = new Array()

function get_menu_links00 () {
    var latmenu = document.getElementById('latmenu');
    var menu_links = new Array()
    var menu_links_nl = latmenu.getElementsByTagName('A');
    var a, p;
    for (var i=0, id; i<menu_links_nl.length; i++) {
        a = menu_links_nl.item(i);
        p = a;
        do {
            p = p.parentNode;
            if (( p.nodeType == 1 ) && (id = p.getAttribute('id')) && (id.indexOf('lnk_') > -1 )) {
                break;
            }
        } while (p.parentNode && id != 'latmenu') ;
        menu_links[i] = new Menu_link (a,p);
    }
    return menu_links;
}

function get_menu_links () {
    var latmenu = document.getElementById('latmenu');
    var menu_links = new Array();
    var menu_links_nl = latmenu.getElementsByTagName('TD');
    var a, p, a_nl;
    for (var i=0, id; i<menu_links_nl.length; i++) {
        p = menu_links_nl.item(i);
        a_nl = p.getElementsByTagName('A');
        if (!( a = a_nl.item(0) ) ) a = null;
        menu_links[i] = new Menu_link (a,p);
    }
    return menu_links;
}

function setup_rollover (i) {
    if (menu_links[i].className && menu_links[i].className == 'on') {
        menu_links[i].imgs[0] = imgdir + bkgds[i % bkgds.length];
        menu_links[i].imgs[1] = '';
    }
    else {
        menu_links[i].imgs[0] = '';
        menu_links[i].imgs[1] = imgdir + bkgds[i % bkgds.length];
    }

    menu_links[i].ancora.onmouseover = rotate_images ;
    menu_links[i].ancora.onmouseout  = rotate_images ;
    menu_links[i].ancora.onclick = stickbg;
    menu_links[i].ancora.menu_link = menu_links[i];
}

function setup_menu_rollovers() {
    menu_links = get_menu_links ();
    for (var i=0; i<menu_links.length; i++) {
        if (menu_links[i].ancora) {
            setup_rollover (i);
        }
    }
}

function init() {
    preload_menu_backgrounds(bkgds,imgdir);
    setup_menu_rollovers();
}

window.onload = init;