Android Confirm [Yes/No] AlertDialog Popup

package com.myapp;

import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;

public class MainActivity extends Activity {

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
        final AlertDialog.Builder adb = new AlertDialog.Builder(this);
        
        // Button1
        final Button btn1 = (Button) findViewById(R.id.button1);
        btn1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
             
				adb.setTitle("Confirm?");
				adb.setMessage("Plese Confirm");
				adb.setNegativeButton("Cancel", null);
				adb.setPositiveButton("Ok", new AlertDialog.OnClickListener() {
					public void onClick(DialogInterface dialog, int arg1) {
						// TODO Auto-generated method stub
						 Toast.makeText(MainActivity.this,"Your Click OK. " ,
					 		     Toast.LENGTH_LONG).show();  
					}
				});
				adb.show();
            	
            }
        });
        
	}
	
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}