function na_preload_img()
{
    var img_list = na_preload_img.arguments;
    if (document.preloadlist == null)
        document.preloadlist = new Array();
    var top = document.preloadlist.length;
    for (var i=0; i < img_list.length-1; i++)
    {
        document.preloadlist[top+i] = new Image;
        document.preloadlist[top+i].src = img_list[i+1];
    }
}

function na_change_img_src(name, nsdoc, rpath, preload)
{
    var img = eval((navigator.appName.indexOf('Netscape', 0) != -1) ? nsdoc+'.'+name : 'document.all.'+name);
    if (name == '')
        return;
    if (img)
    {
        img.altsrc = img.src;
        img.src    = rpath;
    }
}

function na_restore_img_src(name, nsdoc)
{
    var img = eval((navigator.appName.indexOf('Netscape', 0) != -1) ? nsdoc+'.'+name : 'document.all.'+name);
    if (name == '')
        return;
    if (img && img.altsrc)
    {
        img.src    = img.altsrc;
        img.altsrc = null;
    }
}