Drupal 7 pass a custom form fileds input as arguments to the url on submit
$form_state['redirect'] = array(
  'move-quote',
    array(
     'query' =&gt; array(
       'move-quote' =&gt; $form_state['values']['location'],
     ),
    'fragment' =&gt; 'optional',
  ),
);


should work in your submit function. Try also

$form['#submit'][0] = 'custom_form_submit';


and clear your caches.
Also http://drupal.org/node/291680 was helpful