PHP i Javascript

Hvorfor virker dette ikke? Jeg får at vide at: Object doesn't support this property or method!

<?PHP
$tekstFelt = $_GET['felt'];

?>
<html>
<head>
    <title>test</title>
<script LANGUAGE="javascript">
<!--
function DatoTryk(Dato) {
    opener.document.all.<?PHPecho $tekstFelt;?>.value=Dato;
    opener.document.all.<?PHPecho $tekstFelt;?>.focus();
    window.close();
}
//-->
</script>
</head>
<body class="kalenderBody">

<iframe src="indhold.php" frameborder="0" marginwidth="0" marginheight="0" scrolling="no"></iframe>

</body>
</html>

med venlig hilsen
Anders Hansen