var popup = null;

function pop(nr) {
	
	w = 250;
	h = 200;

	aw = (window.screen)? screen.availWidth : 640;
	ah = (window.screen)? screen.availHeight : 450;

	if (popup != null &&  !popup.closed) {

		popup.location = "popup.php?id=" + nr;

	}	

	ustawienia = "left=" + (aw-w)/2 + ",top=" + (ah-h)/2 + ",screenX=" + (aw-w)/2 + ",screenY=" + (ah-h)/2 + ",width=" + w + ",height=" + h + ",innerWidth=" + w + ",innerHeight=" + h + ",toolbar=no,location=no,directories=no,status=no,menubar=no,resizable=no,scrollbars=no";
	popup = window.open('popup.php?id=' + nr, 'popup', ustawienia);

}