function popup(url, name, win_height, win_width) {
    pos_horizon = ((screen.width / 2) - (win_width / 2));
    pos_vertical = ((screen.height / 2) - ((win_height / 2) + 70));
    window.open(url, name, "width=" + win_width + ",height=" + win_height + ",top=" + pos_vertical + ",left=" + pos_horizon);
}