Greetings all,
I must admit I have only briefly looked over your posted code yet there is one thing I would like to mention regarding file uploads with CGI. You must designate your html form as such

<form enctype="multipart/form-data">
[download]

this prepares the browser for possible incoming binary data, aka a file upload. Without it you will get the name of the file but its contents will not get passed to your script. The documentation from CGI regarding file uploads can be found here. Once you have that follow the documentation on how to handle the incoming file and you should be golden.

-InjunJoel