WAAD Authorization Token Access

Hi,

I am working on enabling WAAD support for a single page application, through JavaScript. I have been following this blog post: http://blogs.microsoft.co.il/applisec/2014/03/04/waad-oauth-and-javascript/ I have been able to get the code returned from the authorize endpoint, but have been unable to get a successful token response. I receive a 400 Bad Request and using fiddler I receive:

AADSTS90014: The request body must contain the following parameter: 'client_secret or client_assertion'.

Also I was hoping to to try and use the client_credentials grant_type but am unsure where I can access client_secret from. Any help would greatly be appreciated.