use CGI;
my $query = new CGI;

print $query->startform('POST','upload.cgi','multipart/form-data');
print $query->filefield('upload_file','',30,80);
print $query->submit("Upload"); 
print $query->endform();

# the code above prints this using either startform as shown or start_multipart_form as in the posted code

<form method="post" action="upload.cgi" enctype="multipart/form-data">
<input type="file" name="upload_file"  size=30 maxlength=80 />
<input type="submit" name="Upload" value="Upload" /></form>