title: How to submit a form to a different controller
body: <p>I have a simple blog application with the following associations:</p>
  
  <blockquote>
    <p>Post hasMany Comment</p>
    
    <p>Comment belongsTo Post</p>
  </blockquote>
  
  <p>In the view for a post (<code>PostsController::view</code> action), existing comments are shown and there is a twitter modal popup which shows a form to add a comment.</p>
  
  <p>What do I need to do to insert a new comment in the comments table, from the posts controller view action? How can I call one controller action from another?</p>