PHP / XMl question !

Hello everyone, I am actually programming a website administration tool. I want to store articles within the XML-document and I want to give the author of the article the possibility to combine the articles with MP3-Files, PDF-Documents and more.. All what belongs to the article I want to store within the XML-document. One document for one article ! 1. Is it possible to do that with PHP ? I have already tested EXPAT and I know how to parse XML... I know how to bring XML-elements to the Browser, but.. 2. Is it possible to create, change or modify XML documents using PHP ? Could anyone just give me a simple ? Thats all ! Thanx everyone... MWeber