Firebase android signup

Sign up

 myAut.createUserWithEmailAndPassword(mail,password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if(task.isSuccessful()) {
                        Toast.makeText(getBaseContext(), "Successful!", Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(SignupActivity.this, MainActivity.class));
                    }
                    else
                        Toast.makeText(getBaseContext(), "Problem...", Toast.LENGTH_SHORT).show();
                    dialog.dismiss();
                }
});