Saving xml file from AS3. HELP, HELP!

Hello,

I am trying create a tool for office use which builds a XML file on the users computer. I am able to output XML to the trace screen but I want to take it a step further and have that XML code saved to a document on the users computer. Each time the user enters text and hits submit, a new block of XML needs to be saved to that file. From what I understand, I need a “middle man” application such as Adobe AIR. Can someone point me in the right direction? I have been trying to research this for a few days now. And if AIR is the solution, why is it so non-user friendly to get the extension to work?

If someone can help me I would be eternally grateful. Thanks in advance.