Facebook dotnet app - not finding any user info

Question

I am just starting to learn how to create a facebook app. I am using the MS dotnet libraries.

Following this example and info: http://fbtutorial.qsh.eu/section1/fbml/step6.aspx

I added some code in the default.aspx to print out the user name - but I am not getting any user information back. I understand that some user information is available even if the application is not authorized, such as name or user id.

Example this code returns u=null:

Facebook.Schema.user u = Master.Api.Users.GetInfo();

And this returns 0:

this.Master.Api.Session.UserId

Any suggestions as to why no information is getting returned?

Thanks.