Magento: Add Wysiwyg options in custom module editor

        $wysiwygConfig = Mage::getSingleton('cms/wysiwyg_config')->getConfig(array('add_variables' => true, 'add_widgets' => true, 'files_browser_window_url' => $this->getBaseUrl() . 'admin/cms_wysiwyg_images/index/'));
        $wysiwygConfig["widget_window_url"] = Mage::getSingleton('adminhtml/url')->getUrl('adminhtml/widget/index');
       
        $plugins = $wysiwygConfig->getData("plugins");
        $plugins[0]["options"]["url"] = Mage::getSingleton('adminhtml/url')->getUrl('adminhtml/system_variable/wysiwygPlugin');
        $plugins[0]["options"]["onclick"]["subject"] = "MagentovariablePlugin.loadChooser('" . Mage::getSingleton('adminhtml/url')->getUrl('adminhtml/system_variable/wysiwygPlugin') . "', '{{html_id}}');";
        $plugins = $wysiwygConfig->setData("plugins", $plugins);

// Add the below attribute to editor field
            'config' => $wysiwygConfig,

        $fieldset->addField('content', 'editor', array(
            'name' => 'content',
            'label' => Mage::helper('news')->__('Description'),
            'title' => Mage::helper('news')->__('Description'),
            'style' => 'width:600px; height:250px;',
            'state' => 'html',
            'config' => $wysiwygConfig,
            'wysiwyg' => true,
            'required' => true,
        ));