Add wysiwyg editor in Magento Custom Module

Considering custom module Bd_Demo

Add following function in Bd_Demo_Block_Adminhtml_Demo_Edit

protected function _prepareLayout() {
    parent::_prepareLayout();
    if (Mage::getSingleton('cms/wysiwyg_config')->isEnabled()) {
        $this->getLayout()->getBlock('head')->setCanLoadTinyMce(true);
    }
}

Then use as in grid from  Bd_Demo_Block_Adminhtml_Demo_Edit_Tab_Form
$fieldset->addField("wood_description", "editor", array(
"label" => Mage::helper("woodflooring")->__("Description"),
"class" => "required-entry",
"required" => true,
"name" => "wood_description",
'config'    => Mage::getSingleton('cms/wysiwyg_config')->getConfig(),
'wysiwyg'   => true,
));