// this function allows for extra fields to be added to the file upload widget
function playerfields_form_alter(&$form, $form_state, $form_id) {
  if ($form_id == "feature_node_form" || $form_id == "review_node_form" || $form_id == "story_node_form") {
    // each field can have multiple values, we need to add custom process function to every upload field
    foreach (element_children($form['field_music_player']) as $key) {
     if ($form['field_music_player'][$key]['#type'] == 'filefield_widget') {
        // we have to include original process functions along with the new custom process functions. otherwise field wont be build correctly
        $form['field_music_player'][$key]['#process'] = array('filefield_widget_process', 'artist_widget_process', 'track_widget_process', 'year_widget_process', 'download_widget_process');
        // same with validation function
        $form['field_music_player'][$key]['#element_validate'] = array('filefield_widget_validate', 'artist_widget_validate', 'track_widget_validate', 'year_widget_validate', 'download_widget_validate');
	 }
	}
    // each field can have multiple values, we need to add custom process function to every upload field
    foreach (element_children($form['field_review_player']) as $key) {
      if ($form['field_review_player'][$key]['#type'] == 'filefield_widget') {
        // we have to include original process functions along with the new custom process functions. otherwise field wont be build correctly
        $form['field_review_player'][$key]['#process'] = array('filefield_widget_process', 'artist_widget_process', 'track_widget_process', 'year_widget_process', 'download_widget_process');
        // same with validation function
        $form['field_music_player'][$key]['#element_validate'] = array('filefield_widget_validate', 'artist_widget_validate', 'track_widget_validate', 'year_widget_validate', 'download_widget_validate');
     }
    }
  }
}

//This function adds a downloadable selection field Name text entry field
function download_widget_process($element, $edit, &$form_state, $form) {
    $file = $element['#value'];

    $element['data']['download'] = array(
                '#options' => array(Yes,No),
                '#required' => TRUE,
        '#type' => 'select',
        '#title' => t('Downloadable'),
        '#value' => $file['fid'] ? $file['data']['download'] : ''
    );

    return $element;
}

function track_widget_validate($node, &$form) {
        $playerinfo = $form['values']['field_music_player'];
        foreach ($playerinfo as $int => $value) {
                if ($playerinfo[$int]['data']['track'] == NULL) {
                //if ($form['values']['field_music_player'][0]['data']['track'] == NULL) {
                        form_set_error('', t('You must set a track name for each music file.'));
                }
        }
        //dpm($form);
}