Magento observer event when user has submitted their billing details

Question

I am trying to find a Magento frontend observer event that will trigger on the 'onepage checkout' page when the user has entered their 'Billing' details and clicked the submit button.

I am using Magento 1.7 and have come across this site which has a list of events, however I am unsure which this would be? http://www.nicksays.co.uk/magento-events-cheat-sheet-1-7/

Can anyone suggest anything or point me in the right direction?

Answer 1

The following worked observer worked:

checkout_controller_onepage_save_shipping_method

Answer 2

The data from the billing address is sent to Mage_Checkout_OnepageController::saveBillingAction so you can use controller_action_predispatch_checkout_onepage_savebilling

Then you can access in your observer the data sent through post like this

$post = Mage::app()->getRequest()->getPost();

But this may not fit your needs. If it doesn't then please explain what you want to do ehn you captrure the data.