Login Screen Control

Good day all!!!

I'm new at Android development. Like a few weeks old. I'm using the Login Screen Control which I've have got working up until the point where I have a successful login. Now I'm stuck at how I use the 'successCallback' to close the login screen and open the main application screen. I'm doing the following:

if (result.Property("error") != null) 
                    {
                        failCallback (new LoginScreenFaultDetails {
                            CommonErrorMessage = result.Property("error").Value.ToString()
                        });
                    } else 
                    {
                        Console.WriteLine("logged in successfully");
                        Console.WriteLine("Phase 1");
                        successCallback(); //callback closes login screen but how do I open main screen???
                        Console.WriteLine("Phase 2");
                    }

This is being done inside 'public class CredentialsProvider : ICredentialsProvider'