... beginning same as before ...
my $states = $dbh->selectall_arrayref( ... );
my $tmpl   = HTML::Template->new(filehandle => \*DATA);

$tmpl->param(states =>
   scrolling_list(
      -name     => 'states',
      -values   => [ map $_->{id}, @$states ],
      -size     => 12,
      -multiple => 'why not',
      -labels   => { map {$_->{id} => $_->{name}} @$states },
   ),
);

print header,$tmpl->output;

__DATA__
<form>
<tmpl_var states>
<p><input type="submit" /></p>
</form>