android alert

AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("dfgdf=g")
            .setCancelable(true)
            .setTitle("sdoooo")
            .setPositiveButton("Done", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                dialog.dismiss();
                }
            });
        final AlertDialog alert = builder.create();
       
                alert.show();