Send Notification To The User When Alarm Goes Off?

I m developing an application for creating , deleting and modifing Tasks with a system alarm manager.

Here is the code snippet where i start a service called 'AlarmService'. The role of this service is to create an AlarmManger and send an intent to a receiver called 'AlarmReceiver'. The role of the receiver is to send notification to the user when the alarm goes off.

[HIGH]
public class CreationTaskActivity extends FragmentActivity {
[...]
Intent intent_alarm = new Intent(CreationTaskActivity.this,AlarmService.clas s);[code]....

When i run the application on the emulator, i have this exception:

java.lang.IllegalArgumentException: Enable to start receiver

.java.lang.IllegalArgumentException:contentIntent required....