function tick(){
    var var_download,a_download,a_download_disp;
    var var_users,a_users,a_users_disp;
    var idt;

    a_download      = 12;
    a_download_disp = 4;
    a_users         = 24;
    a_users_disp    = 8;

    var_download = a_download + Math.floor(a_download_disp * Math.random());
    var_users    = a_users + Math.floor(a_users_disp * Math.random());

    document.getElementById('users').innerText    = var_users;
    document.getElementById('download').innerText = var_download;

    window.setTimeout('tick()',Math.floor(6000 * Math.random()));
}
tick();