Should edit details form be in a modal dialog or directly on the page?

I'm building a site that users can login and register on and on the Account Page I am implementing the Edit Details form. My question is, what would be best: the form be right in the page or in a pop up box? (like a fancyBox lightbox) Here is the User Details page:

When the user clicks on "Change details" what would be the best option - for it to pop up in a modal box or for the details to hide and the form to show (right where the details were)?

Answer

A few points here:

1. 
   

   I wouldn't overcomplicated this with a view/edit state. View/edit toggles are good if the user is more likely to be just viewing data and not editing it. If a user visits their Account page, they are likely a very motivated user and want to make a change to either their password or email. Here's how Twitter handles this page:

   
   


2. 
   

   Think about combining "Your account details" and "Change your password" like Twitter does. Not everything they do is perfect, but they've got the account page pretty well figured out ;-)

   
   


3. 
   

   This is an aside, but if "Your likes" is important, rescue it from the Account section. Not sure what the context is, but it might make sense to put that next to "Welcome, Nathan" with a count of the number of likes next to it. ie "Your Likes (3)". That could significantly increase the number of engagements with that feature.