my $response = $mech->mirror($abs_url, $filename)->message;
            print Dumper($response); #print response: [OK, Not Found, Not Modified]
            if($response eq 'Not Found'){
                #responds code here to error trying to download.
            }
            if($response eq 'Not Modified'){
                #responds code here to unmodified download.
            }
            if($response eq 'OK'){
                #responds code here to download successfully.
            }