[web2py] How to upload a file without using SQLFORM ??

[antimatter]

Hi,
how do I upload a file in web2py without using SQLFORM ?
So far, I've got my view with a HTML form:

<form method="post" enctype="multipart/form-data">
        <input name="upload" type="file" size="60" maxlength="100000">
        <input type="Submit" value="Upload">
</form>

Now, how do I write a controller, which uploads the file and save's it
to a specified folder?
But everytime I select a file and upload it, request.vars.upload is
None. How does it work?

Best regards
antimatter