alertDialog

AlertDialog alertDialog = new AlertDialog.Builder(
                        AlertDialogActivity.this).create();

        // Setting Dialog Title
        alertDialog.setTitle("Alert Dialog");

        // Setting Dialog Message
        alertDialog.setMessage("Welcome to AndroidHive.info");

        // Setting Icon to Dialog
        alertDialog.setIcon(R.drawable.tick);

        // Setting OK Button
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                // Write your code here to execute after dialog closed
                Toast.makeText(getApplicationContext(), "You clicked on OK", Toast.LENGTH_SHORT).show();
                }
        });

        // Showing Alert Message
        alertDialog.show()