function popup_window(url, w, h) {
    var width = w;
    var height = h;
    var from_top = 350;
    var from_left = 500;
    var toolbar = 'no';
    var location = 'no';
    var directories = 'no';
    var status = 'no';
    var menubar = 'no';
    var scrollbars = 'yes';
    var resizable = 'yes';
    var atts = 'width=' + width + 'show,height=' + height + ',top=' + from_top + ',screenY=';
    atts += from_top + ',left=' + from_left + ',screenX=' + from_left + ',toolbar=' + toolbar;
    atts += ',location=' + location + ',directories=' + directories + ',status=' + status;
    atts += ',menubar=' + menubar + ',scrollbars=' + scrollbars + ',resizable=' + resizable;
    window.open(url, 'win_name', atts);
}