Customizing a form element

I have a content type. One of the fields is a list that I want to populate from a database. The issue I'm running into is submitting the form. It doesn't submit. I can't put a name on the select that I'm creating. If I take the name out of the element, it submits but the select option isn't saved.

global $user;
	
  dpm($form);


$result = db_query("SELECT nid, title FROM {node} WHERE uid = :uid AND type = 'location'", array('uid' => $user->uid));
$locations = array();
	
foreach ($result as $record) {
	$locations[$record->nid] = t($record->title);
}
	
 $form['field_my_locations'] = array(
       '#type' => 'select',
       '#name' => 'field_my_locations[und]',
       '#title' => t('Locations'),
       '#options' => $locations,
       '#default_value' => $category['selected'],
       '#description' => t('If needed, you can <a href="/node/add/location">create locations</a>.'),
   );
   
?>
<?php print drupal_render($form['field_my_locations']); ?>

<?php print drupal_render_children($form); ?>

If I take the name out, it works but doesn't save. If I leave that in, the form doesn't submit. Please help me so I can try to like drupal