Popup-Fenster mit JavaScript

<html>
<head>
<title>Fenster mit JavaScript</title>
<script type="text/javascript">
<!--
function PopupFenster() {
  F = window.open("datei.htm","Popup","width=400,height=300");
}
// -->
</script>
</head>
<body>
<p><a href="javascript:PopupFenster()">Fenster anzeigen</a></p>
</body>
</html>