Android how to schedule multiple alarms

The Android alarm service is very useful if for scheduling tasks to be done at future dates.  A common use is passing a PendingIntent to the AlarmManager.  When the alarm wakes up the phone, a broadcastReceiver is used to perform the desired actions:

Intent intent = new Intent(a, AlarmReceiver.class);
intent.putExtra("row_id", rowId);
final int alarmId = (int) System.currentTimeMillis();
PendingIntent sender = PendingIntent.getBroadcast(a, alarmId, intent,
    PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager am = (AlarmManager) a.getSystemService(a.ALARM_SERVICE);
    am.set(AlarmManager.RTC_WAKEUP, c.getTimeInMillis(), sender);

Notice the "alarmId" above.  By setting different private request codes as an argument for the getBroadcast function, you can schedule multiple alarms.  If you use the same id, the previous alarms scheduled will be cancelled.