sub compare_dirs {
    
    my ($host, $login, $password, $dir, $rmt_dir) = @_;
    
    my $md = Net::MirrorDir->new(
	    ftpserver       => $host,
	    user            => $login,
	    pass            => $password,
	    localdir        => $dir,
	    remotedir       => $rmt_dir,
	    debug           => 0, # 1 for yes, 0 for no
	    timeout         => 60 # default 30
	);
    
    $md->Connect();
    my ($ref_h_local_files, $ref_h_local_dirs) = $md->ReadLocalDir();
    my ($ref_h_remote_files, $ref_h_remote_dirs) = $md->ReadRemoteDir();
    
    my $ref_a_local_files_not_in_remote = $md->LocalNotInRemote(
	   $ref_h_local_files, 
	   $ref_h_remote_files
	   );
	   
    my $ref_a_remote_files_not_in_local = $md->RemoteNotInLocal(
	   $ref_h_local_files, 
	   $ref_h_remote_files
	   );
    
    #transfer remote files which are not on local system
    foreach my $new_remote_file_not_in_local (@{$ref_a_remote_files_not_in_local}) {
	#transfer the files from remote site to local
	print "$new_remote_file_not_in_local... \n";
    }
    #transfer local files not on remote system
    foreach my $new_local_file_not_in_remote (@{$ref_a_local_files_not_in_remote}) {
	#transfer files from local site to remote site
	print "$new_local_file_not_in_remote... \n";
    }
}