XML Node Update

Hi All,

I have a written a method in SimpleXML parser to update node value for xml file. my method does updates node value but it deletes all the child nodes for it. I want to avoid the deleting of child nodes.

If u have method for updating node plz send it to me.
my xml file,

<?xml version="1.0" encoding="UTF-8"?>
<root> <q1.php language="fr|pt|en|in" editable="Yes">Description<array1 language="fr|pt|en|in" editable="Yes" type="Array" index="Yes">Comment</array1></q1.php></root>


this is my method ,
<?php
$xml = simplexml_load_file('shiva.xml');
$result = $xml->xpath('/root');
$file = 'q1.php';
$result[0]->$file = 'modified';
$fp = @fopen('shiva.xml', "w+");
@fwrite($fp, $xml->asXML());
@fclose($fp);

?>


this is output i'm getting

<?xml version="1.0" encoding="UTF-8"?>
<root> <q1.php language="fr|pt|en|in" editable="Yes">modified</q1.php></root>


plz reply me ASAP