android show an alert dialog

alert-dialog.java

addHomeButton.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
  AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);

  // set title
  alertDialogBuilder.setTitle("Your Title");

  // set dialog message
  alertDialogBuilder
          .setMessage("Click yes to exit!")
          .setCancelable(false)
          .setPositiveButton("Yes",new DialogInterface.OnClickListener() {
              public void onClick(DialogInterface dialog,int id) {
                  // if this button is clicked, close
                  // current activity
                  MainActivity.this.finish();
              }
          })
          .setNegativeButton("No",new DialogInterface.OnClickListener() {
              public void onClick(DialogInterface dialog,int id) {
                  // if this button is clicked, just close
                  // the dialog box and do nothing
                  dialog.cancel();
              }
          });

  // create alert dialog
  AlertDialog alertDialog = alertDialogBuilder.create();

  // show it
  alertDialog.show();
 }
});