<?php

class BookingAdmin extends ModelAdmin {
   static $managed_models = array(
      'Course',
      'Booking'
   );
   
   static $url_segment = 'Bookings';
   static $menu_title = 'Courses & Bookings';
   
   public static $record_controller_class = "BookingAdmin_RecordController";
   

}

class BookingAdmin_RecordController extends ModelAdmin_RecordController {
   

   public function doDuplicate($data, $form, $request) {
      //do something
   }
}

?>

class Course extends DataObject {

...

function getCMSActions(){
      $actions = parent::getCMSActions();
      $Action = new FormAction(
          "doDuplicate",
          "Duplicate Course"
         );
      $actions->push($Action);
      
      return $actions;
   }

...

}

$('#right input[name=action_doDuplicate]').live('click', function(){
      var confirmed = confirm("Duplicate this Record?");
      if(!confirmed) {
         $(this).removeClass('loading')
         return false;
      }

      var form = $('#right form');
      var formAction = form.attr('action') + '?' + $(this).fieldSerialize();

// The POST actually handles the delete
      $.post(formAction, form.formToArray(), function(result){
       // On success, the panel is refreshed and a status message shown.
         $('#right #ModelAdminPanel').html(result);
         
         statusMessage('Successfully duplicated');
      $('#form_actions_right').remove();

// To do - convert everything to jQuery so that this isn't needed
         Behaviour.apply(); // refreshes ComplexTableField
      });
      
      return false;
   });