@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_registration);
    setupUIViews();
    mAuth = FirebaseAuth.getInstance();
    sign.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (validate() ) {
                String user_email = email.getText().toString().trim();
                String user_Password = pass.getText().toString().trim();
                registerUser(user_email, user_Password);

            }
        }
    });
    already.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(Registration.this, Login.class));
        }
    });
}
public void registerUser(String x, String y){
    mAuth.createUserWithEmailAndPassword(x, y)
            .addOnCompleteListener(Registration.this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {
                        Toast.makeText(Registration.this, "Registration Complete", Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(Registration.this, Login.class));
                    } else {
                        Toast.makeText(Registration.this, "Registration failed" + task.getException().getMessage(), Toast.LENGTH_SHORT).show();
                    }
                }
            });

}




        private void setupUIViews() {
            user = (EditText) findViewById(R.id.editText5);
            email = (EditText) findViewById(R.id.Email);
            pass = (EditText) findViewById(R.id.etPassword);
            phone = (EditText) findViewById(R.id.Pnumber);
            first = (EditText) findViewById(R.id.FirstName);
            last = (EditText) findViewById(R.id.LastName);
            sign = (Button) findViewById(R.id.button15);
            already = (TextView) findViewById(R.id.textView);

        }

        private Boolean validate(){
            Boolean result = false;

            String name = first.getText().toString();
            String email1 = email.getText().toString();
            String username = user.getText().toString();
            String lastt = last.getText().toString();
            String password = pass.getText().toString();
            String phone1 = phone.getText().toString();
            if (name.isEmpty() || email1.isEmpty() || lastt.isEmpty() ||
                    password.isEmpty() || phone1.isEmpty() || username.isEmpty()) {
                Toast.makeText(Registration.this, "Please Fill in all fields ", Toast.LENGTH_SHORT).show();
            } else {
                result = true;
            }
            return result;
        }
    }