Na minha atividade principal, que tem um botão. Em seu ouvinte onclick im chamando a função para definir o alarme.O alarme está funcionando, mas iam não conseguir pará-lo .Pode alguém me ajudar

MainActivity.java

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                setalarm();
            }


        });
    }

    private void setalarm() {

        Calendar cal=Calendar.getInstance();
        // cal.set(Calendar.MONTH,6);
        // cal.set(Calendar.YEAR,2013);
        // cal.set(Calendar.DAY_OF_MONTH,12);
        cal.set(Calendar.HOUR_OF_DAY,18);
        cal.set(Calendar.MINUTE,32);
        Intent intent = new Intent(this, Mote.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this.getApplicationContext(), 1253, intent, PendingIntent.FLAG_UPDATE_CURRENT|  Intent.FILL_IN_DATA);

        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);

        alarmManager.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),pendingIntent );
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pendingIntent);
        Toast.makeText(this, "Alarm SET.", Toast.LENGTH_LONG).show();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

Mote.java:

public class Mote  extends BroadcastReceiver{

    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "Alarm worked.", Toast.LENGTH_LONG).show();
        int icon = R.drawable.ic_launcher;
        CharSequence tickerText = "Hello you have to take medicine I am Nitin Sharma";
        long when = System.currentTimeMillis();

        CharSequence contentTitle = "My notification";
        CharSequence contentText = "Hello World!";

        final int NOTIF_ID = 1234;
        NotificationManager notofManager = (NotificationManager)context. getSystemService(Context.NOTIFICATION_SERVICE);
        Intent notificationIntent = new Intent(context, Alset.class);
        PendingIntent contentIntent = PendingIntent.getActivity(context,0, notificationIntent, 0);
        Notification notification = new Notification(icon, tickerText,when );
        notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
        notification.flags = Notification.FLAG_INSISTENT;
        notification.defaults |= Notification.DEFAULT_SOUND;
        notofManager.notify(NOTIF_ID,notification);

        Toast.makeText(context, "Alarm worked.", Toast.LENGTH_LONG).show();

        Intent i = new Intent(context,Alset.class);
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(i);

Alset.java:

public class Alset extends Activity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activitystop); 
        Log.e("IM here ","Im here");

        findViewById(R.id.button1).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Toast.makeText(Alset.this, "Stop the alrm now", Toast.LENGTH_LONG).show();
            }
        });
    }   
}

Quando o alarme iniciar, receberei o retorno de chamada noOnReceive() método. De lá eu vou para a atividade Alset onde eu mantive um botão de parada. Como faço para parar o alarme daqui?

NOTA: - Estou codificando o tempo para definir o alarme.