Navigate to another user control after button click from code behind

Sep 25, 2013 at 7:30 AM
I want to navigate to another user control from my login user control button click.
The button click first authenticates user then loads another user control.How can I do this with mui,tried Navigation Commands getting the runtime error that "Object ref is not set to instance of object."
Please suggest
Sep 26, 2013 at 10:19 AM
Please provide the sample code.