Problem with Loading, rewrituing config.xml

[SnakeMedia]

I have been readden this site: "Create Skinnable Application Using Flex + AIR" But i do not understand because code was broken by disallowed tag <!-- nosupport --> etc.. What does it happen? Please write orginal code! Because i am tried at loading and writing Config.xml with Adobe AIr. I want to plan my simple application. I am sad because German's websites are using only Flash CS3 / CS4. I want to find only "Flex 3 and Air 1.5"

Please tell about example with file and filestream - If i want to know about code on Flex and Air.

I am developing at my expensive applications for SnakeMedia's Homepage.

How does my application find a file config.xml like this "file exists"
and "folder exists". and rewri´te file - if my application will to restart and loads currect setup or configure. Please!!!

I hope you because you help me back. I want to learn about config.xml with save, write, update....

Thanks best regards