Symphony.

    class extension_sitename extends Extension {

        public function about() {
            return array(
                'name'          => 'Site Name',
                'version'       => '1.0',
                'release-date'  => '2009-01-02',
                'author'        => array(
                    'name'          => 'Stephen Bau',
                    'website'       => 'http://www.domain7.com/',
                    'email'         => 'stephen@domain7.com'
                ),
                'description'   => 'Symphony System Preference for modifying the site name'
            );
        }

        public function getSubscribedDelegates(){
            return array(
                array(
                    'page' => '/system/preferences/',
                    'delegate' => 'AddCustomPreferenceFieldsets',
                    'callback' => 'appendPreferences'
                ),

                array(
                    'page' => '/system/preferences/',
                    'delegate' => 'Save',
                    'callback' => '__SavePreferences'
                ),

                array(
                    'page' => '/backend/',
                    'delegate' => 'AppendPageAlert',
                    'callback' => '__AppendAlert'
                ),
            );
        }

        public function __SavePreferences(){
            $settings = $_POST['settings'];

            $setting_group = 'general';
            $setting_name = 'sitename';
            $setting_value = $settings['general']['sitename'];

            $this->_Parent->Configuration->set($setting_name, $setting_value, $setting_group);
            $this->_Parent->saveConfig();

    //  redirect(URL . '/symphony/system/preferences/?action=sitename-saved');

        }

        public function __AppendAlert($context){
            if($_REQUEST['action'] == 'sitename-saved'){
                $this->_Parent->Page->pageAlert('The site name was updated successfully.', AdministrationPage::PAGE_ALERT_NOTICE);
            }
        }

        public function appendPreferences($context){
            $group = new XMLElement('fieldset');
            $group->setAttribute('class', 'settings');
            $group->appendChild(new XMLElement('legend', 'Site Name'));         

            $sitename = $this->_Parent->Configuration->get('sitename', 'general');
            $label = new XMLElement('label', 'Website Name');           
            $label->appendChild(Widget::Input('settings[general][sitename]', $sitename, 'text'));

            $group->appendChild($label);                        
            $context['wrapper']->appendChild($group);
        }
    }