function newWindow(url, width, height) {
var win_l = (screen.width - width) / 2;
var win_t = (screen.height - height) / 2;
var open = window.open(url, "", "height="+ height +",width="+ width +",top="+ win_t +",left="+ win_l +",toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=yes,resizable=no");
}
tex. så får du klart ändra location, toolbar å alla de där efter behag.