android dialog box example
runOnUiThread(new Runnable() { @Override public void run() { if (!isFinishing()){ new AlertDialog.Builder(YourActivity.this) .setTitle("Your Alert") .setMessage("Your Message") .setCancelable(false) .setPositiveButton("ok", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // Whatever... } }).show(); } } });