<html>
<head>
<script type="text/javascript">
function setTarget() {
document.forms[0].target = _parentName;
}
</script>
</head>
<body onload="setTarget();">
<p>Popup
</p>
<form action="http://www.google.fi/search">
<input type="text" name="q" value="vaadin" />
<input type="submit" value="Google!"/>
</form>
</body>
</html>