MS MVC gets blocks from rails

Sergio Pereira and I started writing some stories today for Javascript helpers in Mvc Contrib. During our talk we had to deal with rendering html elements with inner html and javascript blocks ensuring they all got closed but still allowing the ultimate in flexibility for the developer. MvcToolkit goes about this with a using(…) pattern on their FormHelper. The one disadvantage of this is that the using block will be limited to only a single block. What happens when you need to render a block for onSuccess and onFailure?