function Popup(url, left, top, width, height) {
	properties = "left=" + left + ",top=" + top + ",width=" + width + ",height=" + height + ",scrollbars=yes,menubars=no,toolbars=no,resizable=yes";
	popup = window.open(url, "", properties);
	if (parseInt(navigator.appVersion) >= 4) {
		popup.window.focus();
	}
	return false;
}

function CenterPopup(url, width, height) {
	var left = (screen.width - width) / 2;
	var top = (screen.height - height) / 2;
	return Popup(url, left, top, width, height);
}