mAuth.signInWithEmailAndPassword(emailInp, passInp).addOnCompleteListener(LoginActivity.this, new OnCompleteListener<AuthResult>() {
                        @Override
                        public void onComplete(@NonNull Task<AuthResult> task) {
                            FirebaseUser currentUser = mAuth.getCurrentUser();
                            //if login succeed
                            if (currentUser != null) {
                                Intent main = new Intent(LoginActivity.this, MainActivity.class);
                                Bundle b = new Bundle();
                                b.putString("email", emailInp);
                                main.putExtras(b);
                                mAuth.getCurrentUser();
                                startActivity(main);
                            } else
                                //when the login check is failed
                                Toast.makeText(LoginActivity.this, "Incorrect Email or Password", Toast.LENGTH_SHORT).show();
                        }
                    });