magento event not working

Question

I'm trying to obvserve the adminhtml_block_salesrule_actions_prepareform event thats dispatched in the app/code/core/Mage/Adminhtml/Block/Promo/Quote/Edit/Tab/Actions.php file in the _prepareForm() method. But I keep getting an error message and I'm not sure why?

Warning: Mage_Core_Model_App::dispatchEvent() [mage-core-model-app.dispatchevent]: Node no longer exists in /var/www/server/www.site.com/app/code/core/Mage/Core/Model/App.php on line 1249

This is the part of my config.xml in my module - I'm not doing something wrong am I?

  <adminhtml>
        <events>
            <adminhtml_block_salesrule_actions_prepareform>
                <shoppingcartrules>
                    <class>shoppingcartrules/observer</class>
                    <method>prepareForm</method>
                </shoppingcartrules>
            </adminhtml_block_salesrule_actions_prepareform>
        </events>
    </adminhtml>

Answer 1

I figured it out...was missing the node in my XML.

<adminhtml>
    <events>
        <adminhtml_block_salesrule_actions_prepareform>
            <observers>
                <shoppingcartrules>
                    <class>shoppingcartrules/observer</class>
                    <method>prepareForm</method>
                </shoppingcartrules>
            </observers>
        </adminhtml_block_salesrule_actions_prepareform>
    </events>
</adminhtml>