XML Class to read & write

Hi.
I am wondering if anyone has a drop in class that is easy to read & write nested xml files. Ive seen and got a few that read very basic xml files.
but i am not good enough to make it read & write nested tags.

ie
<config>
<Screen>
<Size>10</Size>
<somethingelse>blah blah</somethingelse>
<Screen>
<Next setting>test</Next setting>
<Anotherone>xxxxxxx</Anotherone>
</config>

tks