android - The notification doesn't appear? -

i have notification:

private void sendsimplenotification(){       boolean permanent = preferencemanager.getdefaultsharedpreferences(context).getboolean("permanent", false);      if(permanent) {         notificationcompat.builder notificationbuilder = new notificationcompat.builder(service.this);         notificationbuilder.setcontenttitle("title");         notificationbuilder.setcontenttext("context");         notificationbuilder.setticker("tickertext");         notificationbuilder.setwhen(system.currenttimemillis());         notificationbuilder.setsmallicon(r.drawable.ic_stat_icon);          intent notificationintent = new intent(this, service.class);         pendingintent contentintent = pendingintent.getactivity(this, 0, notificationintent, 0);          notificationbuilder.setcontentintent(contentintent);         notificationbuilder.setdefaults(notification.default_sound | notification.default_lights | notification.default_vibrate);         mnotificationmanager.notify(1, notificationbuilder.build());     }      else{         mnotificationmanager.cancel(simple_notification_id);           }  } 

my goal when checkboxpreferences checked notification appears, otherwise unchecked disappears.. goes wrong , notification doesn't appear/disappear when checkbox in preferences screen checked/unchecked. have call sendsimplenotification somewhere? don't know error.