function popup(url,name,w, h) {
	var l = screen.width / 2 - w / 2;
	var t = screen.height / 2 - h / 2;
        var w_ = w+3;
        var h_ = h+3;
        var Win = window.open(url,name,'width=' + w_ + ', height=' + h_ + ', left=' + l + ', top=' + t);
	Win.moveTo(l, t);
}