Problem with xml file in CodeIgniter

[eluser]greedyman[/eluser]
I want to create a xml file to config database file (you don't need metion to config file in CI, this is my new idea). I found on internet but I'm only got some libraries help me create xml file. Beside create file, I want to do other action as save to file (somewhere in project), read file, delete elements, update elements. Could you tell me which library can help me do this? Thanks!

[eluser]Massaki[/eluser]
On phpclasses.org you can search for "array2xml" and/or "xml2array". Then make a few modifications according your necessities