Local Notification before IOS4

Question

Possible Duplicate:
Is local Notification feature available in iphone os below 4.0?

Hi my dear friends:

I am now developing a sceduling thing like a reminder, and I use the localNotification to awake my app however,It seemed that the localNotification do not work before IOS4

so my question is

Is there any mechanism can wrok instead of LocalNotification before IOS4? and before IOS4 how to awake an app when user exit it ?

Thanks!!!