Flash Text Editor: Write To Text File On Server

Hello.

I have a flash text editor with bold, italics and link button.

The editor pulls in external text from a text file on server: example - about.txt

I want so that the text in the about.txt is externally pulled into the text editor, then text is edited with bold, italic and links.

Then when ready, click a submit button and the text will be written/saved back to the about.txt on the server.

How to do this so that only raw text and the basic <b> <i> <a href> tags are posted back to the text file on the server.

This would work with flash and a server script via php or xml.

Thanks in advance.