Proses Registrasi di Main Activity

package com.example.lenovo.myapplication;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import com.example.lenovo.myapplication.proses.proses_crud;

public class MainActivity extends AppCompatActivity {

    EditText username, password, ulangpass;
    Button btn_daftar;
    TextView login;
    AlertDialog.Builder builder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        username = (EditText) findViewById(R.id.username);
        password = (EditText) findViewById(R.id.password);
        ulangpass = (EditText) findViewById(R.id.password_konf);
        btn_daftar = (Button) findViewById(R.id.button);

        btn_daftar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (username.getText().toString().equals("")||password.getText().toString().equals("")){
                    builder = new AlertDialog.Builder(FormRegister.this);
                    builder.setTitle("Informasi");
                    builder.setMessage("Your fill not input..!!");
                    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            dialogInterface.dismiss();
                        }
                    });
                    AlertDialog alertDialog = builder.create();
                    alertDialog.show();
                }else if (!password.getText().toString().equals(ulangpass.getText().toString())){
                    builder = new AlertDialog.Builder(FormRegister.this);
                    builder.setTitle("Informsi");
                    builder.setMessage("Maaf password dan ulangi password tidak sama...!");
                    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            dialogInterface.dismiss();
                        }
                    });
                    AlertDialog alertDialog = builder.create();
                    alertDialog.show();
                }
                else {
                    proses_crud backgroundTask = new proses_crud(FormRegister.this);
                     backgroundTask.execute("Daftar", username.getText().toString(),password.getText().toString());
                }
            }
        });
    }


}