my @args;

    my %chkopts = (
      help => $help,
      b    => $backup,
      u    => $upd_sybase,
      s    => $silent,
    );

    while (my ($k, $v) = each %chkopts) {
      next unless defined $v;
      push @args, $v ? "--$k" : "--no$k";
    }    

    my %chkargs = (
      update   => $update,
      server   => $server,
      user     => $user,
      password => $password,
    );

    while (my ($k, $v) = each %chkargs) {
      next unless defined $v;
      push @args "$k=$v";
    }