Helo! Xml item appending problem

[shim2k]

Hello, I'm new to this forum, hope to help and get help here!

XML File:

<?xml version="1.0"?>

<sites xml:lang="EN">

<site>

<name>Google</name>

<value>http://www.google.com</value>

</site>

<site>

<name>Wikipedia</name>

<value>http://www.wikipedia.org</value>

</site>
</sites>

I want to add another <site> item to this xml with PHP.
I know to read and write XML with PHP but I still can't do it, can you help me?

thanks.