Android - Caixa de diálogo com botões

 import android.app.AlertDialog;  
 import android.content.DialogInterface;  

 AlertDialog.Builder builder = new AlertDialog.Builder(this);  
 builder.setMessage("Are you sure?");  
 builder.setTitle("Warning");  
 builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {  
    public void onClick(DialogInterface dialog,int which) {  
                 dialog.cancel();                           
  }});  
 builder.setNegativeButton("No", new DialogInterface.OnClickListener() {  
    public void onClick(DialogInterface dialog,int which) {  
                 dialog.cancel();                            
  }}).create().show();