#!/usr/bin/Perl
[download]

perl (and *nix) are case sensitive so that is usually spelled:

#!/usr/bin/perl
[download]

    open(FILE1,$file1);
[download]

You should verify that the file opened correctly:

    open FILE1, '<', $file1 or die "Cannot open '$file1' because: $!";
[download]

if (($filename eq "") || (defined $filename eq 'false')) {
[download]

defined $filename will never be eq to the string 'false'