[Zope] How to create a file from a form?

[paolomatador@libero.it]

Hi All, I'm trying to create a DTML Document, or a DTML Method or a 
text file from an input form in a web page.
I have a form with some input text, some checkboxes and radiobutton 
and a submit.
On submit I have to create a text file and append some text at the 
end of that file.
I can use the manage_addDTMLDocument method to create that file, even 
if I would create a text file, and not a DTML Document, but I dont 
know how to append any text at the end of the file or how to edit the 
file.
Can Anyone Help Me?
Thanx