Simple Question... I hope

Ok, I'm uploading a file to a 3rd party. The file is being uploaded to
an https site with a cgi extension. The 3rd party finally provided me
with a snippet of their Perl code. They see the attempt coming
through, but there is no data. I understand how all this works... i
think there's just a dot i'm not connecting somewhere. PLEASE HELP...
Thanks in advance!!!

In my html file I have...
<font size="4" color="#000066">File: </font><INPUT TYPE="file"
NAME="XML_DATA" size="47"></p>
<INPUT TYPE="submit" NAME="submitButtonName" VALUE="Submit Query"></p>

See below:
Here is the Perl snippet of what they're doing...

    my $query = new CGI;
    my (@data) = $query->param;
    my (%data,$key);
    foreach $key (@data)
    {
      $data{$key} = $query->param($key);
      &logXmlOrder ("key($key) data($data{$key})");
    }
    read(STDIN,$xmlcontent,$ENV{'CONTENT_LENGTH'});
    &logXmlOrder ("Content=$xmlcontent");

Here is what they're telling me is logged on their side:

key(submitButtonName) data(Submit Query)
Content=