FacebookAuthenticationResult FacebookOAuthClientAuthorizer not found?

I just download the facebook c# sdk. I am trying to get the facebook silverlight example to work.

I am looking at CSSilverlightInBrowser

When I clicked on the "login" button, it redirect to the file

slfbinbrowserlogin.aspx

and开发者_如何学Python then my browser just said "Compile Error" Compilation Error Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0246: The type or namespace name 'FacebookAuthenticationResult' could not be found (are you missing a using directive or an assembly reference?)

Am I missing out somthing?

thanks

diing