How to upload a file, using Python Mechanize, with a twist :)

Ok I have only been using Mechanize for one day, so be nice :P

I would like complete a form including one (or two if possible) file upload style fields. The ones where you click, and it lets you browse for a file.

(I want to automate the uploading of a .torrent to a private tracker / site)

Now the two issues I have had is on the site none of the forms have names, so I have been using the index of the form to choose them.

br.select_form(nr=4)

Now the problem is I want to also upload a file when I submit the form. There are two file fields and I dont think I am properly specifying each one. Here is a "print" of the form made using "print br.form"

<POST http://www.###.##.##/takeupload.php multipart/form-data
  <HiddenControl(MAX_FILE_SIZE=1000000) (readonly)>
  <TextControl(<None>=http://www.###.##.##:81/announce.php?passkey=###) (readonly)>
  <FileControl(file=<No files added>)>
  <TextControl(name=)>
  <SelectControl(type=[*0, 23, 22, 1, 10, 7, 12, 4, 21, 17, 18, 13, 58, 16, 15, 56, 20, 60, 5, 19, 6, 55, 57, 63, 9])>
  <CheckboxControl(strip=[strip])>
  <FileControl(nfo=<No files added>)>
  <TextareaControl(descr=)>
  <SubmitControl(<None>=Do it!) (readonly)>>

I tried this code hoping it would just default to the first one:

br.form.add_file(open(filename), 'text/plain', filename)

But, it gives this error

    Traceback (most recent call last):
  File "script.py", line 53, in <module>
    br.form.add_file(open(filename), 'text/plain', filename)
  File "/usr/local/lib/python2.6/dist-packages/mechanize-0.2.4-py2.6.egg/mechanize/_form.py", line 2968, in add_file
    self.find_control(name, "file", id=id, label=label, nr=nr).add_file(
  File "/usr/local/lib/python2.6/dist-packages/mechanize-0.2.4-py2.6.egg/mechanize/_form.py", line 3101, in find_control
    return self._find_control(name, type, kind, id, label, predicate, nr)
  File "/usr/local/lib/python2.6/dist-packages/mechanize-0.2.4-py2.6.egg/mechanize/_form.py", line 3183, in _find_control
    raise AmbiguityError("more than one control matching "+description)
mechanize._form.AmbiguityError: more than one control matching type 'file'

So how do I:

• tell it which file field I meant
• or upload the file a different way

Thank you very much :)