var param = "copyhistory=no,directories=no,menubar=no,location=no,resizable=yes,scrollbars=yes";

function window_open(url, name, w, h)
{
    new_window = window.open(url, name, 'width=' + w + ', height=' + h + ", " + param);
    new_window.focus();
}

function leaf_appear(){
document.getElementById('leaf').style.display='block';
}

function leaf_hide(){
document.getElementById('leaf').style.display='none';
}