Can't pass attributes to dropdown

[eluser]maddtechwf[/eluser]
I've been looking at this page and can't quite figure something out.

I have a dropdown box that I need to pass a CSS class to but don't see that in the manual. Any suggestions?

I've tried the following but I did not work.

Code:

<?php
$state_attr = array('name' => 'state', 'id' => 'state', 'class' => 'span2');
      $state_opt = array('AL' => 'AL', 'AK' => 'AK', 'AZ' => 'AZ', 'AR' => 'AR', 'CA' => 'CA', 'CO' => 'CO', 'CT' => 'CT', 'DE' => 'DE', 'FL' => 'FL', 'GA' => 'GA', 'HI' => 'HI', 'ID' => 'ID',
      'IL' => 'IL', 'IN' => 'IN', 'IA' => 'IA', 'KS' => 'KS', 'KY' => 'KY', 'LA' => 'LA', 'ME' => 'ME', 'MD' => 'MD', 'MA' => 'MA', 'MI' => 'MI', 'MN' => 'MN', 'MS' => 'MS', 'MO' => 'MO', 'MT' => 'MT',
      'NE' => 'NE', 'NV' => 'NV', 'NH' => 'NH', 'NJ' => 'NJ', 'NM' => 'NM', 'NY' => 'NY', 'NC' => 'NC', 'ND' => 'ND', 'OH' => 'OH', 'OK' => 'OK', 'OR' => 'OR', 'PA' => 'PA', 'RI' => 'RI', 'SC' => 'SC',
      'SD' => 'SD', 'TN' => 'TN', 'TX' => 'TX', 'UT' => 'UT', 'VT' => 'VT', 'VA' => 'VA', 'WA' => 'WA', 'WV' => 'WV', 'WI' => 'WI', 'WY' => 'WY');

echo form_dropdown($state_attr, $state_opt,'TX');
?>

[eluser]sv3tli0[/eluser]

Code:

form_dropdown($name = '', $options = array(), $selected = array(), $extra = '')

First is your select box name, then all options, then selected and at last id/class..