Android : Alarm manager won't trigger

I've tried to get alarm manager to trigger but it won't, I can't get why. Here is the code I have in my main activity:

    public void scheduleAlarm() 
{       
    Calendar calendar = Calendar.getInstance();
    calendar.setTimeInMillis(System.currentTimeMillis());
    calendar.set(Calendar.HOUR_OF_DAY, 11);
    calendar.set(Calendar.MINUTE, 32);
    Intent intentAlarm = new Intent(this, AlarmReceiver.class);

    AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

    alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), PendingIntent.getBroadcast(this,1,  intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
}

and this is what I have in my class alarmreceiver:

public class AlarmReceiver extends BroadcastReceiver {
NotificationCompat.Builder mBuilder;
@Override
public void onReceive(Context context, Intent intent) {
    Toast.makeText(context, "You got pawned", Toast.LENGTH_LONG).show();
    NotificationCompat.Builder mBuilder =
            new NotificationCompat.Builder(context)
            .setSmallIcon(R.drawable.ic_launcher)
            .setContentTitle("My notification")
            .setContentText("Hello World!");

    // Sets an ID for the notification
    int mNotificationId = 001;
    // Gets an instance of the NotificationManager service
    NotificationManager mNotifyMgr = 
            (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    // Builds the notification and issues it.
    mNotifyMgr.notify(mNotificationId, mBuilder.build());
}

}

anyone knows why it doesn't work?

Thanks in advance!