$field = 
  Rose::HTML::Form::Field::SelectBox->new(
    name     => 'whatever', 
    multiple => 1,
    options  => [ 1 => 'One', 2 => 'Two', 3 => 'Three' ],
    size     => 3);

$field->input_value([ 1, 3 ]);

print $field->html;
##</code><code>##

<select multiple name="whatever" size="3">
<option selected value="1">1</option>
<option value="One">One</option>
<option value="2">2</option>
<option value="Two">Two</option>
<option selected value="3">3</option>
<option value="Three">Three</option>
</select>

##</code><code>##

$form = Rose::HTML::Form->new;

$form->add_fields
(
  whatever =>
  {
    type     => 'select box',
    multiple => 1,
    options  => [ 1 => 'One', 2 => 'Two', 3 => 'Three' ], 
    size     => 3,
  },
  ...
);

# Pass in form params from various sources:

# Hashref
$form->params({ whatever => [ 1, 3 ] });

# CGI object
$form->params_from_cgi($cgi); # $cgi "isa" CGI

# Apache request object (mod_perl 1 or 2)
$form->params_from_apache($r);

# Initialize the fields based on params
$form->init_fields();

##</code><code>##

print $form->start_html,
      $form->field('whatever')->html,
      ...
      $form->end_html;

##</code><code>##

[% form.start_html %]
[% form.field('whatever').html %]
...
[% form.end_html %]