drupal #default_value not working for #type radios i am editing a form in drupal 7.1 and want to add a group of radios
    $form['yearofstudy']= array(
   '#title'=&gt;'What is your year of study',
   '#type' =&gt; 'radios',
   '#options' =&gt; array(1=&gt;'first year',2=&gt;'second year',3=&gt;'third year',4=&gt;'fourth year',5=&gt;'fifth year'),
   '#required' =&gt; true,
   '#default_value'=&gt;array(1,0,0,0,0),
   );

The problem:
I intended the first option to be selected but this is what am getting

Please help.
A radio group can only have one radio selected. Did you try '1' as default value?