How to dynamically generate a filename based on a form field value?

Hey all, my first post here so please let me know if this is in the wrong subfolder... here is my question:

I need the "contact.xml" (which is what the xml file being saved will be named using the current code) to be a "field value"... so basically the html form that this page processes would have "file_name" as a field and then this script your looking at would say ***name the .xml file whatever text "field_name" has in it***  see below for script, and the author's page where I found this code: http://www.xmlfiles.com/articles/michael/htmlxml/default.asp

I'm a web designer, not a heavy coder but I've been asked to put this functionality together, so any help is greatly appreciated.


'-----------BEGIN CODE FOR processForm.asp------------

<%

'----------------------------------------------- ...