function popup(url, name, args) {
	if (typeof(popupWin) != "object") {
		popupWin = window.open(url, name, args);
	} else {
		if (! popupWin.closed) {
			popupWin.location.href = url;
		} else {
			popupWin = window.open(url, name, args);
		}
	}
	popupWin.focus();
	window.onunload = function() { popupWin.close(); }
}