Drupal无线电形式

Question

我在Drupal 6中选择Radios按钮时遇到问题。
我如何知道提交中选择了哪些无线电？

 $db = db_query("Select * from {people}");
  $types = array();
    while($node = db_fetch_object($db)){
        $nodetitle = $node->fam." ".$node->name." ".$node->patr;
        $ar = array($node->uId => $nodetitle);
        $types=array_merge($types, $ar);
    }
 $form['Doc']['object'] = array(
            '#type' => 'radios',
            '#title' => "ss",
            '#options'  => $types
        );
 $form['Doc']['submit_upload'] = array(
    '#type'  =>  'submit', 
    '#value'  =>  'OK'
  );
.........
function get_form_doc_submit($form, &$form_state){
$radio=$form_state['values']['Doc']['object'];
    //How do I know Which Radios selected here?
}