Editing XML using PHP

[theboss_edgar]

Hello, everyone. I'm newbie in PHP. I have a little problem. I have an existing XML file, that has some data. First let me show the XML Structure(it's an example):

<?xml version="1.0" encoding="iso-8859-1"?>
<people>
<person>
<First_Name>Edgar</First_Name>
<Last_Name>Polanco</Last_Name>
</person>
<person>
<First_Name>Nairoby</First_Name>
<Last_Name>Del Rosario</Last_Name>
</person>
</people>

Ok, what I want is add new data to the XML file, add data to the First_Name and Last_Name Child, but using PHP. I want that the php add the first name and last name inside a person label and the every person label must be inside the people label.

I hope you understand. Any suggestion will be appreciated.

Thanks.