MainActivity

private FirebaseAuth mAuth;
    private EditText edit_txtemail,edit_txtpass;
	
	 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mAuth = FirebaseAuth.getInstance();
		
		}
		
		@Override
		public void onStart() {
        super.onStart();
        // Check if user is signed in (non-null) and update UI accordingly.
        FirebaseUser currentUser = mAuth.getCurrentUser();
        updateUI(currentUser);
    }
	
	 private void updateUI(FirebaseUser user) {

    }