drupal7 add cancel button

Cancel button to take them back to the previous page.





function hook_form_alter(&$form, &$form_state, $form_id) {
  $form = array();

  $form['actions']['cancel'] = array(
    '#type'   => 'submit',
    '#value'  => t('Cancel'),
    '#submit' => array('callback_for_cancel_button'),
    '#limit_validation_errors' => array(),
  );

  return $form;
}

function callback_for_cancel_button($form, &$form_state) {
  $url = $_GET['destination'] ? $_GET['destination'] : '';
  drupal_goto($url);
}